Outlook OST File is in Use and Cannot be Accessed: Error Resolved

OST files are created when Exchange cached mode is on and act as a mirror image of the Exchange Database mailbox on Windows machine. A replica of the Exchange mailbox data is stored on the client machine. User can delete or modify data even if Outlook are not connected to Exchange account.

When Outlook connected to Exchange Server, the modified items are synced to OST file. The OST file may go into inaccessible mode and user might see the error "Outlook OST File is in Use and Cannot be Accessed".

Reasons: Outlook OST File is in Use and Cannot be Accessed

There are several reasons why this error message can occur. This can happen for any of the following reasons:

Expert Solution to Solve Outlook OST File Corruption Issues

However, user can protect OST file data from damage by using the simplest and easiest Exchange OST Recovery Software. RecoveryTools can be used to troubleshoot OST related issues, the tool recovers offline files and save them to PST format.

Download Now Purchase Now

Step by Step Guide to Use this Software

How to Fix OST File is in Use and Cannot be Accessed Error?

User can use manual workarounds to eliminate the error messages where Outlook OST file is in use and cannot be accessed. These solutions are:

Solution 1: Use ScanOST.exe Tool

Offline storage table issues can be resolved by running the "OST Integrity Check" tool. The built-in utility fixes minor corruption issues in these files. The only limitation of this utility is that it cannot Repair Corrupted OST File in Outlook.

Note: ScanOST.exe is available in Outlook 2007 and earlier, and is not available in the latest version of the application. Better to Use Inbox Repair Tool in Outlook 2019, 2016, 2013.

Step-by-Step Working for Executing ScanOST.exe:

  • Exit MS Outlook application
  • Launch ScanOST.exe


  • In case, if Outlook application is running, the following window will appear:

    Outlook OST File is in Use and Cannot be Accessed

  • If the tool prompts for 'Profile name' provide the accurate name
  • Further, if it prompts for 'Work Offline' or 'Connect', click on 'Connect'
  • Select appropriate options such as 'Scan all folders' etc. as per requirement


  • Select the 'Repair Errors' checkbox to command tool to automatically check and remove the discrepancies. Afterwards, Click on 'Begin Scan'.

    Repair Outlook OST File is in Use and Cannot be Accessed Error

Note: If the checkbox associated with Repair Errors is unchecked, the tool will check for problems but will not correct them properly.

Detect OST Storage Location:

User can find the location of the OST file by following these steps:

  • Click on 'Start' menu and type 'Run' in the available box
  • In the 'Open' box, type


    App Data

  • Next, locate the appropriate OST file in the then appeared Windows Explorer.

However, if there is serious corruption in the file It is recommended to fix OST file to remove any existing error messages. The procedure for using this is described in the next section.

Solution 2: Save OST to Outlook Data File

This is because Outlook 2010 and the latest versions do not include ScanOST.exe tool. We are recommends saving OST file into Outlook data file to remove related issues. This can be done through the import and export options available in the application.

Procedure to Save OST File in Outlook Data File:

  • In 'File' tab, select 'Open' and then click on 'Import' option from right pane


  • Select 'Import from another program or file' in the then appeared 'Import and Export Wizard'

    Fix Outlook OST File is in Use and Cannot be Accessed Issue

  • 'Import a file' window will appear, select 'Outlook data file (.pst)' and click 'Next'


  • Click on 'Browse' and then select the file that has to be imported


  • In the same window, select appropriate option to replace, allow or ignore import of duplicate items. Click on 'Next' button

    Corrected Outlook OST File is in Use and Cannot be Accessed Error

  • Provide accurate storage path for saving the file
  • At last, click on 'Finish' to exit the wizard.

Note: The steps above apply to different versions of Outlook 2013 and 2010. The overall conversion process may vary depending on the lower version or higher version of the application.

Limitations Associated with Manual Methods

This section describes the procedure for running ScanOST.exe and save OST file, but these methods have some limitations. They are very long and have the potential to lose data. Manually saving offline files to tables that stored personal data is not recommended. This can cause the loss of important information stored in inbox.

Additionally, the structure of e-mail messages and embedded attachments may lose integrity during conversion. The built-in utility ScanOST.exe may help remove the minimum level of corruption. But it's not a higher level of corruption problem. Additionally, this utility has been removed from the latest version of the application, so user can use a simple and reliable solution to get rid of the OST related error messages.


RecoveryTools™ is based on core business standards that ensure "perfection" and "precision" throughout the entire process.

© 2023 RecoveryTools All Rights Reserved

WhatsApp Call Now

Live Chat