{"id":4318,"date":"2016-11-11T10:08:38","date_gmt":"2016-11-11T10:08:38","guid":{"rendered":"https:\/\/www.stellarinfo.com\/blog\/?p=4318"},"modified":"2026-08-07T06:40:34","modified_gmt":"2026-08-07T06:40:34","slug":"fix-outlook-pst-cannot-be-opened","status":"publish","type":"post","link":"https:\/\/www.stellarinfo.com\/blog\/fix-outlook-pst-cannot-be-opened\/","title":{"rendered":"How to Fix \u201cOutlook .PST cannot be Opened\u201d Error?"},"content":{"rendered":"

When you configure your email account with POP3, it creates an Outlook data file (PST) on your local storage to download and store mailbox data from the mail server. This PST file stores all the mailbox items, such as emails, attachments, contacts, calendar, notes, and tasks. However, sometimes, this PST file becomes inaccessible, causing Outlook to display an error when you try to open it. The complete error may look like this:<\/p>

“The file C:\\Users\\username\\AppData\\Local\\Microsoft\\user name\\username.pst is in use and cannot be accessed. Close any application that is using this file, and then try again. You might need to restart your computer.”<\/em><\/strong><\/p>

\"Outlook<\/figure>

Although the error message shows that the PST file is being used by some other application, it can also occur due to several other reasons. Below, we will discuss the reasons behind this error and see how to fix it.<\/p>

Reasons for ‘Outlook PST cannot be Opened’ Error<\/strong><\/h2>

There could be several reasons that can trigger this error in Outlook, such as:<\/p>

    \n
  1. Outlook.exe is running in the background.<\/li>\n\n\n\n
  2. PST file backup is running in the background.<\/li>\n\n\n\n
  3. An application conflicting with Outlook.<\/li>\n\n\n\n
  4. Outlook data file is locked by OneDrive.<\/li>\n\n\n\n
  5. Faulty or incompatible third-party add-ins.<\/li>\n\n\n\n
  6. Damaged or corrupt PST file<\/a>.<\/li>\n\n\n\n
  7. Insufficient file permissions.<\/li>\n\n\n\n
  8. Outdated Outlook application.<\/li>\n\n\n\n
  9. Corrupt Outlook Profile.<\/li>\n\n\n\n
  10.  PST file has exceeded its recommended size limit<\/li>\n<\/ol>

    Methods to Fix ‘Outlook PST cannot be opened’ Error<\/strong><\/h2>

    Follow these methods in the given order to resolve this Outlook PST file error.<\/p>

    Method 1: Check File Permissions<\/strong><\/h3>

    If you don’t have sufficient permissions to access, read, or modify the PST file, then you may encounter the PST cannot be opened error. To verify the file permissions, navigate to the PST file, right-click it, select Properties, and open the Security tab. Ensure that your user account has Read, Write, Modify, and Read & Execute permissions for the file.<\/p>

    Also, under the General tab, make sure the Read-only attribute is not selected. If it is, clear the checkbox, click Apply, and then OK.<\/p>

    Alternatively, you can run Outlook as administrator to overcome permission-related issues.  <\/p>

    Method 2: Update Outlook and Windows<\/strong><\/h3>

    To fix any compatibility issues with Outlook and the mail server, you must check and update Outlook and Windows. This will bring patches and features that may resolve this issue in Outlook. The steps to update Outlook are as follows:<\/p>