{"id":328,"date":"2018-09-05T12:42:38","date_gmt":"2018-09-05T12:42:38","guid":{"rendered":"https:\/\/www.arysontechnologies.com\/updates\/?p=328"},"modified":"2025-10-06T10:40:28","modified_gmt":"2025-10-06T10:40:28","slug":"fix-error-outlook-ost-in-use-cannot-be-accessed","status":"publish","type":"post","link":"https:\/\/www.arysontechnologies.com\/updates\/fix-error-outlook-ost-in-use-cannot-be-accessed\/","title":{"rendered":"How to Fix Outlook &#8220;OST File in Use Cannot Be Accessed&#8221; Error"},"content":{"rendered":"<p class=\"block_sum\"><em>OST file is in use and cannot be accessed message in Outlook happens when the OST file is locked, corrupted, or is held up by a different program. It can be fixed either by shutting down contradictory applications, by disabling Cached Exchange Mode, or by repairing the file. To provide a stable and legitimate solution, the <a href=\"https:\/\/www.arysontechnologies.com\/ost-recovery.html\" target=\"_blank\" rel=\"noopener\"><strong>Aryson OST Recovery Tool <\/strong><\/a>will fix any unavailable OST files, preserve all the mailbox information, and reclaim the entire Outlook functionality in a fast and safe manner. Proceed with this blog to Fix \u201cOST File is in use and cannot be accessed\u201d Error:<\/em><span class=\"block_btn\"><a class=\"custom-download-btn\" href=\"https:\/\/www.arysontechnologies.com\/demo-version\/Aryson-OST-Recovery-Demo.exe\" rel=\"nofollow\"> Download Now<\/a>\u00a0\u00a0<a class=\"custom-buy-btn\" href=\"https:\/\/www.arysontechnologies.com\/ost-recovery\/order-now.html\" rel=\"nofollow\"> Purchase Now<\/a><\/span><\/p>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_82_2 counter-hierarchy ez-toc-counter ez-toc-light-blue ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title ez-toc-toggle\" style=\"cursor:pointer\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.arysontechnologies.com\/updates\/fix-error-outlook-ost-in-use-cannot-be-accessed\/#What_is_the_Outlook_OST_file_in_use_error\" >What is the Outlook OST file in use error?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.arysontechnologies.com\/updates\/fix-error-outlook-ost-in-use-cannot-be-accessed\/#Common_Causes_of_the_Error\" >Common Causes of the Error<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.arysontechnologies.com\/updates\/fix-error-outlook-ost-in-use-cannot-be-accessed\/#How_to_Fix_%E2%80%9COST_File_is_in_use_and_cannot_be_accessed%E2%80%9D_Error\" >How to Fix \u201cOST File is in use and cannot be accessed\u201d Error<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.arysontechnologies.com\/updates\/fix-error-outlook-ost-in-use-cannot-be-accessed\/#Method_1_Quit_Outlook_and_the_Processes\" >Method 1: Quit Outlook and the Processes.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.arysontechnologies.com\/updates\/fix-error-outlook-ost-in-use-cannot-be-accessed\/#Method_2_Turn_off_Security_Programs_for_Outlook_OST_file_repair\" >Method 2: Turn off Security Programs for Outlook OST file repair.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.arysontechnologies.com\/updates\/fix-error-outlook-ost-in-use-cannot-be-accessed\/#Method_3_Check_Account_settings\" >Method 3: Check Account settings.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.arysontechnologies.com\/updates\/fix-error-outlook-ost-in-use-cannot-be-accessed\/#Option_4_Turn_off_Problematic_Add-ins\" >Option 4: Turn off Problematic Add-ins<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.arysontechnologies.com\/updates\/fix-error-outlook-ost-in-use-cannot-be-accessed\/#Method_5_Disable_Cached_Exchange_Mode\" >Method 5: Disable Cached Exchange Mode.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/www.arysontechnologies.com\/updates\/fix-error-outlook-ost-in-use-cannot-be-accessed\/#Method_6_Rebuild_the_OST_File\" >Method 6: Rebuild the OST File<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/www.arysontechnologies.com\/updates\/fix-error-outlook-ost-in-use-cannot-be-accessed\/#Recover_the_OST_files_Before_Conversion\" >Recover the OST files Before Conversion<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/www.arysontechnologies.com\/updates\/fix-error-outlook-ost-in-use-cannot-be-accessed\/#Method_7_Convert_OST_File_to_Repair_the_OST_file_in_Outlook\" >Method 7: Convert OST File to Repair the OST file in Outlook<\/a><ul class='ez-toc-list-level-4' ><li class='ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/www.arysontechnologies.com\/updates\/fix-error-outlook-ost-in-use-cannot-be-accessed\/#You_simply_have_to_take_the_following_simple_steps_to_make_the_conversion_process_easier\" >You simply have to take the following simple steps to make the conversion process easier:<\/a><\/li><\/ul><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/www.arysontechnologies.com\/updates\/fix-error-outlook-ost-in-use-cannot-be-accessed\/#Conclusion\" >Conclusion<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/www.arysontechnologies.com\/updates\/fix-error-outlook-ost-in-use-cannot-be-accessed\/#Frequently_Asked_Questions\" >Frequently Asked Questions<\/a><\/li><\/ul><\/li><\/ul><\/nav><\/div>\n<h2 class=\"main_heading\"><span class=\"ez-toc-section\" id=\"What_is_the_Outlook_OST_file_in_use_error\"><\/span>What is the Outlook OST file in use error?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>The error of Outlook, which states that the OST file is in use and can not be accessed normally, happens when the Offline Storage Table (OST) file gets locked or unreadable. This issue prevents the opening or synchronizing of emails in Outlook and, therefore, disrupts regular work since the file contains a local copy of your mailbox, which you can use when you are not online.<\/p>\n<h2 class=\"main_heading\"><span class=\"ez-toc-section\" id=\"Common_Causes_of_the_Error\"><\/span>Common Causes of the Error<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<ul>\n<li>Background programs: There are times when Outlook is not able to access the OST file since the file is already in use by another application in the background.<\/li>\n<li>Corruption of the OST file: When the file is corrupted, this prevents Outlook from reading and opening the file.<\/li>\n<li>Unexpected Outlook shutdown: In cases where the Outlook file has been prematurely closed, the OST file might be locked, and it becomes difficult to access.<\/li>\n<li>Synchronization issues: This Outlook error can also be caused by errors during the synchronization process with the mail server.<\/li>\n<\/ul>\n<p>With the awareness of these potential causes, you will be able to find the specific cause of the problem and choose the best remedy to address it.<\/p>\n<h2 class=\"main_heading\"><span class=\"ez-toc-section\" id=\"How_to_Fix_%E2%80%9COST_File_is_in_use_and_cannot_be_accessed%E2%80%9D_Error\"><\/span>How to Fix \u201cOST File is in use and cannot be accessed\u201d Error<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>The error message states that Outlook cannot read the OST file as it is used by another process. In some cases, a reboot can fix the problem, however, when that fails, use the following ways to OST file in use error in Outlook:<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Method_1_Quit_Outlook_and_the_Processes\"><\/span>Method 1: Quit Outlook and the Processes.<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ol>\n<li>Close Outlook and open Task Manager (Ctrl + Shift + Esc).<\/li>\n<li>On the Process tab, look for Outlook, Skype for Business (LYNC), Communicator, or UCMAPI.<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-1907\" src=\"https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image1.webp\" alt=\"On the Process tab, look for Outlook\" width=\"700\" height=\"390\" srcset=\"https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image1.webp 700w, https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image1-300x167.webp 300w, https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image1-698x390.webp 698w\" sizes=\"auto, (max-width: 700px) 100vw, 700px\" \/><\/li>\n<li>End these tasks one by one.<\/li>\n<li>Restart Outlook and verify whether or not the problem has been solved.<\/li>\n<\/ol>\n<h3 class=\"main_heading\"><span class=\"ez-toc-section\" id=\"Method_2_Turn_off_Security_Programs_for_Outlook_OST_file_repair\"><\/span>Method 2: Turn off Security Programs for Outlook OST file repair.<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Proceed with these steps too. May be it can be helpful to Fix \u201cOST File is in use and cannot be accessed\u201d Error:<\/p>\n<ol>\n<li>The OST file can be locked by antivirus or Firewall software.<\/li>\n<li>Turn them off and restart Outlook.<\/li>\n<li>In case Outlook is running well, then add Outlook and the OST file as exceptions to your security tool.<\/li>\n<\/ol>\n<h3 class=\"main_heading\"><span class=\"ez-toc-section\" id=\"Method_3_Check_Account_settings\"><\/span>Method 3: Check Account settings.<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ol>\n<li>Incorrect DNS, port, or proxy configurations can cause errors.<\/li>\n<li>To set up an account in Outlook, use File Account Settings Account Settings.<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-1908\" src=\"https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-2.webp\" alt=\" File Account Settings Account Settings\" width=\"700\" height=\"390\" srcset=\"https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-2.webp 700w, https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-2-300x167.webp 300w, https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-2-698x390.webp 698w\" sizes=\"auto, (max-width: 700px) 100vw, 700px\" \/><\/li>\n<li>Choose your account &#8211; Next to Change &#8211; Next to More Settings &#8211; Advanced.<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-1909\" src=\"https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-3.webp\" alt=\"Next to More Settings\" width=\"700\" height=\"390\" srcset=\"https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-3.webp 700w, https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-3-300x167.webp 300w, https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-3-698x390.webp 698w\" sizes=\"auto, (max-width: 700px) 100vw, 700px\" \/><\/li>\n<\/ol>\n<h3 class=\"main_heading\"><span class=\"ez-toc-section\" id=\"Option_4_Turn_off_Problematic_Add-ins\"><\/span>Option 4: Turn off Problematic Add-ins<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Also, you should find the OST file locked by another process. Then, turn off problematic Add-ins with these steps:<\/p>\n<ol>\n<li>Boot Outlook into Safe Mode (Windows + R &#8211; outlook \/safe).<\/li>\n<li>In the case that Outlook starts correctly, turn off add-ins:<\/li>\n<li>Go to File &gt; Options &gt; Add-ins.<\/li>\n<li>In Manage, choose COM Add-ins and then go.<\/li>\n<li>Select all add-ins and restart Outlook.<\/li>\n<li>Enable the add-ins one at a time to locate the buggy one and delete it forever.<\/li>\n<\/ol>\n<h3 class=\"main_heading\"><span class=\"ez-toc-section\" id=\"Method_5_Disable_Cached_Exchange_Mode\"><\/span>Method 5: Disable Cached Exchange Mode.<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Cached Exchange Mode stores mailbox information on the local disk drive, and this could lead to conflict. Here are the steps to fix the Outlook OST file is inaccessible:<\/p>\n<ol>\n<li>Access Control Panel, Mail, E-mail Accounts.<\/li>\n<li>Choose your account &#8211; click on Change.<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-1910\" src=\"https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-4.webp\" alt=\"Choose your account - click on Change\" width=\"700\" height=\"390\" srcset=\"https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-4.webp 700w, https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-4-300x167.webp 300w, https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-4-698x390.webp 698w\" sizes=\"auto, (max-width: 700px) 100vw, 700px\" \/><\/li>\n<li>Then click No to Use Cached Exchange Mode and restart Outlook.<\/li>\n<li>When the error is deleted, this means that there is a problem with the OST file.<\/li>\n<\/ol>\n<h3 class=\"main_heading\"><span class=\"ez-toc-section\" id=\"Method_6_Rebuild_the_OST_File\"><\/span>Method 6: Rebuild the OST File<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>In case of corruption of the OST, recreate it: Follow the given steps to resolve the OST file access error:<\/p>\n<ol>\n<li>Open Look and then navigate to the OST file location.<\/li>\n<li>Change the extension of the OST file to a .bak file (e.g, a file with the name of an e-mail address, such as abcxyz.com.ost.bak).<\/li>\n<li>Restart Outlook, and a new OST file will be generated and synchronized with the server.<\/li>\n<\/ol>\n<h3 class=\"main_heading\"><span class=\"ez-toc-section\" id=\"Recover_the_OST_files_Before_Conversion\"><\/span>Recover the OST files Before Conversion<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Along with several reasons, one reason can be your corrupted outlook data file. So all you need to do is recover those OST files first. For ease of the user, we are here with the <strong>Aryson OST Recovery tool<\/strong> which will help you restore the OST file with ease. Download the software and <a href=\"https:\/\/www.arysontechnologies.com\/blog\/how-to-backup-ost-file\/\" target=\"_blank\" rel=\"noopener\"><strong>get your OST file backup<\/strong><\/a> within a few clicks. There is no risk of data loss during the recovery process. When you recover the OST file then move to the next section.<\/p>\n<h3 class=\"main_heading\"><span class=\"ez-toc-section\" id=\"Method_7_Convert_OST_File_to_Repair_the_OST_file_in_Outlook\"><\/span>Method 7: Convert OST File to Repair the OST file in Outlook<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Sometimes, users get into trouble with corrupted OST files or struggle to move their information between platforms. Under these circumstances, the <a href=\"https:\/\/www.arysontechnologies.com\/convert-ost-to-pst-online.html\" target=\"_blank\" rel=\"noopener\"><strong>Aryson OST to PST Converter<\/strong><\/a> is the solution. This software has an elaborate preview panel that allows you to preview all the mailbox contents before actual conversion. In addition, it offers the possibility to export only specified folders or emails, which saves time and storage. Also, it will eliminate similar items to maintain your backup clean and tidy. On top of that, its batch processing ability enables you to work with multiple files of OST simultaneously without compromising the processing speed or data quality.<\/p>\n<h4 class=\"main_heading\"><span class=\"ez-toc-section\" id=\"You_simply_have_to_take_the_following_simple_steps_to_make_the_conversion_process_easier\"><\/span>You simply have to take the following simple steps to make the conversion process easier:<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<ol>\n<li>To start with, download the Aryson OST to PST Converter on your computer.<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-1911\" src=\"https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-5.webp\" alt=\"download the Aryson OST to PST Converter on your computer\" width=\"700\" height=\"390\" srcset=\"https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-5.webp 700w, https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-5-300x167.webp 300w, https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-5-698x390.webp 698w\" sizes=\"auto, (max-width: 700px) 100vw, 700px\" \/><\/li>\n<li>Then, open the program and press Select File to select your OST files.<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-1912\" src=\"https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-6.webp\" alt=\"open the program and press Select File to select your OST\" width=\"700\" height=\"390\" srcset=\"https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-6.webp 700w, https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-6-300x167.webp 300w, https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-6-698x390.webp 698w\" sizes=\"auto, (max-width: 700px) 100vw, 700px\" \/><\/li>\n<li>Then, preview the items of the mailbox, like emails, contacts, and calendars, in the preview panel to verify their accuracy.<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-1913\" src=\"https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-7.webp\" alt=\"preview the items of the mailbox\" width=\"700\" height=\"390\" srcset=\"https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-7.webp 700w, https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-7-300x167.webp 300w, https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-7-698x390.webp 698w\" sizes=\"auto, (max-width: 700px) 100vw, 700px\" \/><\/li>\n<li>Then you have to select Save As, and the preferred format is PST.<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-1914\" src=\"https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-8.webp\" alt=\"select Save As, and the preferred format is PST\" width=\"700\" height=\"390\" srcset=\"https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-8.webp 700w, https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-8-300x167.webp 300w, https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-8-698x390.webp 698w\" sizes=\"auto, (max-width: 700px) 100vw, 700px\" \/><\/li>\n<li>Explore and specify the destination folder in which you wish to save the converted files.<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-1915\" src=\"https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-9.webp\" alt=\"specify the destination folder in which you wish to save\" width=\"700\" height=\"390\" srcset=\"https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-9.webp 700w, https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-9-300x167.webp 300w, https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-9-698x390.webp 698w\" sizes=\"auto, (max-width: 700px) 100vw, 700px\" \/><\/li>\n<li>Lastly, press the Convert button and locate your PST files at the location.<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-1916\" src=\"https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-10.webp\" alt=\"Convert button and locate your PST files\" width=\"700\" height=\"390\" srcset=\"https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-10.webp 700w, https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-10-300x167.webp 300w, https:\/\/www.arysontechnologies.com\/updates\/wp-content\/uploads\/2018\/09\/image-10-698x390.webp 698w\" sizes=\"auto, (max-width: 700px) 100vw, 700px\" \/><\/li>\n<\/ol>\n<h2 class=\"main_heading\"><span class=\"ez-toc-section\" id=\"Conclusion\"><\/span>Conclusion<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>The error message of the inability to operate the OST file, which is in use and is not accessible, can stop Outlook and deny access to valuable email. The manual approach to it will not work, particularly when dealing with large or corrupt OST files. The Aryson OST to PST Converter is a safe solution to fix \u201cOST File is in use and cannot be accessed\u201d Error. It restores all mailbox information, eliminates duplicates, and changes OST files to PST and other formats with complete accuracy. Users will be able to gain full access to Outlook, secure their email, and clean their mailbox effectively without losing any data.<\/p>\n<h3 class=\"faq-main_heading\"><span class=\"ez-toc-section\" id=\"Frequently_Asked_Questions\"><\/span>Frequently Asked Questions<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n<div class=\"schema-faq wp-block-yoast-faq-block\"><div class=\"schema-faq-section\" id=\"faq-question-1759746213393\"><strong class=\"schema-faq-question\"><strong>Q1. What does the error \u201cOST file is in use and cannot be accessed\u201d mean in Outlook?<\/strong><\/strong> <p class=\"schema-faq-answer\"><strong>Ans<\/strong>: This error usually appears when another program or background process is using the OST file, preventing Outlook from accessing it properly.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1759746244476\"><strong class=\"schema-faq-question\"><strong>Q2. Why am I getting the \u201cOST file is in use\u201d error even when Outlook is closed?<\/strong><\/strong> <p class=\"schema-faq-answer\"><strong>Ans<\/strong>:It can happen if background Outlook processes are still running, if add-ins are interfering, or if antivirus software is scanning the OST file.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1759746263188\"><strong class=\"schema-faq-question\"><strong>Q3. How do I check if Outlook is running in the background?<\/strong><\/strong> <p class=\"schema-faq-answer\"><strong>Ans<\/strong>: Open Task Manager (Ctrl + Shift + Esc) and look for OUTLOOK.EXE. If it is still running after closing Outlook, end the task to release the OST file.\u00a0<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1759746285474\"><strong class=\"schema-faq-question\"><strong>Q4. Does restarting my computer fix the \u201cOST file is in use\u201d error?<\/strong><\/strong> <p class=\"schema-faq-answer\"><strong>Ans<\/strong>: In many cases, yes. Restarting closes all background processes and frees up the OST file for Outlook to use again.<\/p> <\/div> <\/div>\n\n\n<div class=\"kk-star-ratings kksr-auto kksr-align-left kksr-valign-bottom\"\n    data-payload='{&quot;align&quot;:&quot;left&quot;,&quot;id&quot;:&quot;328&quot;,&quot;slug&quot;:&quot;default&quot;,&quot;valign&quot;:&quot;bottom&quot;,&quot;ignore&quot;:&quot;&quot;,&quot;reference&quot;:&quot;auto&quot;,&quot;class&quot;:&quot;&quot;,&quot;count&quot;:&quot;3&quot;,&quot;legendonly&quot;:&quot;&quot;,&quot;readonly&quot;:&quot;&quot;,&quot;score&quot;:&quot;5&quot;,&quot;starsonly&quot;:&quot;&quot;,&quot;best&quot;:&quot;5&quot;,&quot;gap&quot;:&quot;5&quot;,&quot;greet&quot;:&quot;Rate this post&quot;,&quot;legend&quot;:&quot;5\\\/5 - (3 votes)&quot;,&quot;size&quot;:&quot;24&quot;,&quot;title&quot;:&quot;How to Fix Outlook \\u0026quot;OST File in Use Cannot Be Accessed\\u0026quot; Error&quot;,&quot;width&quot;:&quot;142.5&quot;,&quot;_legend&quot;:&quot;{score}\\\/{best} - ({count} {votes})&quot;,&quot;font_factor&quot;:&quot;1.25&quot;}'>\n            \n<div class=\"kksr-stars\">\n    \n<div class=\"kksr-stars-inactive\">\n            <div class=\"kksr-star\" data-star=\"1\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" data-star=\"2\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" data-star=\"3\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" data-star=\"4\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" data-star=\"5\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n    <\/div>\n    \n<div class=\"kksr-stars-active\" style=\"width: 142.5px;\">\n            <div class=\"kksr-star\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n    <\/div>\n<\/div>\n                \n\n<div class=\"kksr-legend\" style=\"font-size: 19.2px;\">\n            5\/5 - (3 votes)    <\/div>\n    <\/div>\n","protected":false},"excerpt":{"rendered":"<p>OST file is in use and cannot be accessed message in Outlook happens when the OST file is locked, corrupted,<a class=\"read-more ml-1 main-read-more\" href=\"https:\/\/www.arysontechnologies.com\/updates\/fix-error-outlook-ost-in-use-cannot-be-accessed\/\">Read More<\/a><\/p>\n","protected":false},"author":7,"featured_media":329,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-328","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-error"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.4 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>How to Fix Outlook &quot;OST File in Use Cannot Be Accessed&quot; Error<\/title>\n<meta name=\"description\" content=\"Explore methods to fix OST File is in use and Cannot be Accessed error. Get the solution to resolve OST file is in use and cannot be accessed.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.arysontechnologies.com\/updates\/fix-error-outlook-ost-in-use-cannot-be-accessed\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"How to Fix Outlook &quot;OST File in Use Cannot Be Accessed&quot; Error\" \/>\n<meta property=\"og:description\" content=\"Explore methods to fix OST File is in use and Cannot be Accessed error. 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He enjoys conducting research and generating information that assists database administrators, businesses, and novices in resolving issues with MS SQL Server, MySQL databases, Cloud Computing, and Microsoft Exchange.\",\"sameAs\":[\"https:\\\/\\\/www.linkedin.com\\\/in\\\/rohan-wiese-writer\\\/\"],\"url\":\"https:\\\/\\\/www.arysontechnologies.com\\\/updates\\\/author\\\/rohanwiese\\\/\"},{\"@type\":\"Question\",\"@id\":\"https:\\\/\\\/www.arysontechnologies.com\\\/updates\\\/fix-error-outlook-ost-in-use-cannot-be-accessed\\\/#faq-question-1759746213393\",\"position\":1,\"url\":\"https:\\\/\\\/www.arysontechnologies.com\\\/updates\\\/fix-error-outlook-ost-in-use-cannot-be-accessed\\\/#faq-question-1759746213393\",\"name\":\"Q1. What does the error \u201cOST file is in use and cannot be accessed\u201d mean in Outlook?\",\"answerCount\":1,\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"<strong>Ans<\\\/strong>: This error usually appears when another program or background process is using the OST file, preventing Outlook from accessing it properly.\",\"inLanguage\":\"en-US\"},\"inLanguage\":\"en-US\"},{\"@type\":\"Question\",\"@id\":\"https:\\\/\\\/www.arysontechnologies.com\\\/updates\\\/fix-error-outlook-ost-in-use-cannot-be-accessed\\\/#faq-question-1759746244476\",\"position\":2,\"url\":\"https:\\\/\\\/www.arysontechnologies.com\\\/updates\\\/fix-error-outlook-ost-in-use-cannot-be-accessed\\\/#faq-question-1759746244476\",\"name\":\"Q2. Why am I getting the \u201cOST file is in use\u201d error even when Outlook is closed?\",\"answerCount\":1,\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"<strong>Ans<\\\/strong>:It can happen if background Outlook processes are still running, if add-ins are interfering, or if antivirus software is scanning the OST file.\",\"inLanguage\":\"en-US\"},\"inLanguage\":\"en-US\"},{\"@type\":\"Question\",\"@id\":\"https:\\\/\\\/www.arysontechnologies.com\\\/updates\\\/fix-error-outlook-ost-in-use-cannot-be-accessed\\\/#faq-question-1759746263188\",\"position\":3,\"url\":\"https:\\\/\\\/www.arysontechnologies.com\\\/updates\\\/fix-error-outlook-ost-in-use-cannot-be-accessed\\\/#faq-question-1759746263188\",\"name\":\"Q3. How do I check if Outlook is running in the background?\",\"answerCount\":1,\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"<strong>Ans<\\\/strong>: Open Task Manager (Ctrl + Shift + Esc) and look for OUTLOOK.EXE. If it is still running after closing Outlook, end the task to release the OST file.\u00a0\",\"inLanguage\":\"en-US\"},\"inLanguage\":\"en-US\"},{\"@type\":\"Question\",\"@id\":\"https:\\\/\\\/www.arysontechnologies.com\\\/updates\\\/fix-error-outlook-ost-in-use-cannot-be-accessed\\\/#faq-question-1759746285474\",\"position\":4,\"url\":\"https:\\\/\\\/www.arysontechnologies.com\\\/updates\\\/fix-error-outlook-ost-in-use-cannot-be-accessed\\\/#faq-question-1759746285474\",\"name\":\"Q4. Does restarting my computer fix the \u201cOST file is in use\u201d error?\",\"answerCount\":1,\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"<strong>Ans<\\\/strong>: In many cases, yes. 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He enjoys conducting research and generating information that assists database administrators, businesses, and novices in resolving issues with MS SQL Server, MySQL databases, Cloud Computing, and Microsoft Exchange.","sameAs":["https:\/\/www.linkedin.com\/in\/rohan-wiese-writer\/"],"url":"https:\/\/www.arysontechnologies.com\/updates\/author\/rohanwiese\/"},{"@type":"Question","@id":"https:\/\/www.arysontechnologies.com\/updates\/fix-error-outlook-ost-in-use-cannot-be-accessed\/#faq-question-1759746213393","position":1,"url":"https:\/\/www.arysontechnologies.com\/updates\/fix-error-outlook-ost-in-use-cannot-be-accessed\/#faq-question-1759746213393","name":"Q1. What does the error \u201cOST file is in use and cannot be accessed\u201d mean in Outlook?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"<strong>Ans<\/strong>: This error usually appears when another program or background process is using the OST file, preventing Outlook from accessing it properly.","inLanguage":"en-US"},"inLanguage":"en-US"},{"@type":"Question","@id":"https:\/\/www.arysontechnologies.com\/updates\/fix-error-outlook-ost-in-use-cannot-be-accessed\/#faq-question-1759746244476","position":2,"url":"https:\/\/www.arysontechnologies.com\/updates\/fix-error-outlook-ost-in-use-cannot-be-accessed\/#faq-question-1759746244476","name":"Q2. Why am I getting the \u201cOST file is in use\u201d error even when Outlook is closed?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"<strong>Ans<\/strong>:It can happen if background Outlook processes are still running, if add-ins are interfering, or if antivirus software is scanning the OST file.","inLanguage":"en-US"},"inLanguage":"en-US"},{"@type":"Question","@id":"https:\/\/www.arysontechnologies.com\/updates\/fix-error-outlook-ost-in-use-cannot-be-accessed\/#faq-question-1759746263188","position":3,"url":"https:\/\/www.arysontechnologies.com\/updates\/fix-error-outlook-ost-in-use-cannot-be-accessed\/#faq-question-1759746263188","name":"Q3. How do I check if Outlook is running in the background?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"<strong>Ans<\/strong>: Open Task Manager (Ctrl + Shift + Esc) and look for OUTLOOK.EXE. If it is still running after closing Outlook, end the task to release the OST file.\u00a0","inLanguage":"en-US"},"inLanguage":"en-US"},{"@type":"Question","@id":"https:\/\/www.arysontechnologies.com\/updates\/fix-error-outlook-ost-in-use-cannot-be-accessed\/#faq-question-1759746285474","position":4,"url":"https:\/\/www.arysontechnologies.com\/updates\/fix-error-outlook-ost-in-use-cannot-be-accessed\/#faq-question-1759746285474","name":"Q4. Does restarting my computer fix the \u201cOST file is in use\u201d error?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"<strong>Ans<\/strong>: In many cases, yes. Restarting closes all background processes and frees up the OST file for Outlook to use again.","inLanguage":"en-US"},"inLanguage":"en-US"}]}},"_links":{"self":[{"href":"https:\/\/www.arysontechnologies.com\/updates\/wp-json\/wp\/v2\/posts\/328","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.arysontechnologies.com\/updates\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.arysontechnologies.com\/updates\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.arysontechnologies.com\/updates\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/www.arysontechnologies.com\/updates\/wp-json\/wp\/v2\/comments?post=328"}],"version-history":[{"count":9,"href":"https:\/\/www.arysontechnologies.com\/updates\/wp-json\/wp\/v2\/posts\/328\/revisions"}],"predecessor-version":[{"id":1918,"href":"https:\/\/www.arysontechnologies.com\/updates\/wp-json\/wp\/v2\/posts\/328\/revisions\/1918"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.arysontechnologies.com\/updates\/wp-json\/wp\/v2\/media\/329"}],"wp:attachment":[{"href":"https:\/\/www.arysontechnologies.com\/updates\/wp-json\/wp\/v2\/media?parent=328"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.arysontechnologies.com\/updates\/wp-json\/wp\/v2\/categories?post=328"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.arysontechnologies.com\/updates\/wp-json\/wp\/v2\/tags?post=328"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}