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How to Rename OST File in MS Outlook? Easy and Quick Steps

  Mark Regan
Mark Regan
Published: April 24th, 2025 • 8 Min Read

Do you want to rename OST file in outlook but don’t know how to do it? Well you don’t need to worry. There are several ways that you can use it. Just read this article and understand the easy steps to instantly change OST file name with just a few clicks.

OST files (Offline storage file) are local copies or offline folders of user’s mailbox data in the exchange server. OST files are important for all the professionals nowadays. Sometimes users start encountering issues with their OST files which they want to fix by changing its name. However there can be several different reasons to rename OST file in Outlook 2007, 2010, 2013, 2016, 2019 & 2021.

If you also want to change OST file name and make it more secure, then try the methods described in the article. We have also provided valuable information that you should definitely know before changing the name of your OST file.

Table of Content Hide
    1. Reasons to Rename OST File
    2. Precautions Before Renaming OST File
    3. How to Change OST File Name in Outlook?
    4. Rename OST File in MS Outlook
    5. Change OST File Name in Outlook 2021, 2019, 2016, 2013, & 2010
    6. How to Rename OST File in Outlook 2007?
    7. Advanced Method: Permanently Changing OST File Name
    8. Rebuilding OST File: When Renaming Isn’t Enough
    9. Changed OST File Name But Still Can’t Access Its Data?
    10. Common Errors and Troubleshooting Tips
    11. Best Practice for Managing OST Files
    12. Conclusion

Reasons to Rename OST File

Following issues can be fixed by changing the name of OST file:

  • The OST file is freezed and you are unable to open, view and edit it.
  • OST corruption issues, restricted to send and receive emails.
  • The OST file is not working and showing errors.
  • The Outlook OST file is taking so much time to load.
  • Outlook is disconnected and unable to synchronize the local mailbox.

Precautions Before Renaming OST File

  • Always take backup of the OST file before renaming it. Even though an OST file caches copies of mailbox data, backing them up ensures that any unsynchronized emails or customized settings are preserved.
  • Verify Microsoft Outlook is properly closed and not running in the background. Renaming an OST file can lead to file corruption or data loss issues when Outlook is running.
  • Check Microsoft Outlook is completely closed and not running in the background. Renaming an OST file can lead to file corruption or data loss issues.
  • If your Outlook is connected to an Exchange Server, verify that connection is active. After renaming the OST file, Outlook will recreate the OST file or sync data from the server.
  • Make a note of the current OST file location and its name as it helps you to easily find and restore original OST files.
  • If you’re part of a corporate environment, notify your IT administrator before making changes to Outlook data files, as it may conflict with company politics or configurations.

How to Change OST File Name in Outlook?

Following are the mOST popular methods to rename OST file in different versions of Outlook such as 2019, 2016, 2013, 2010, and 2007. Moreover if you still fail to :

Rename OST File in MS Outlook

  1. Close the Outlook app and go to the default path of OST file:
    • C:\Users \YourProfileName\AppData\Local\Microsoft\Outlook
  2. After navigating the default .OST file location.
  3. Right click and type the new desired name for your OST file and press Enter.

Change OST File Name in Outlook 2021, 2019, 2016, 2013, & 2010

  1. Open MS Outlook and click on the File tab to rename OST file.
  2. Click on Info button then select Account Settings> Account Settings.
  3. Open the “Data Files” tab and choose the file which is “set as default”.
  4. Find the option Open folder/ Open File Location then click on it.
  5. Change the OST file as per your choice and press Enter key.

How to Rename OST File in Outlook 2007?

  1. Simply Click File> Info> Account Setting> Account Setting.
  2. Choose Default tab> Open Folder.
  3. Right click on the OST file and change its name.

Advanced Method: Permanently Changing OST File Name

  1. Clear all running apps in the background like Outlook.
  2. Open Control Panel and Click on Mail and select Email Accounts.
  3. Select your account and click on Change.
  4. Uncheck use Cached Exchange Mode.
  5. Click Next, then finish and restart Outlook after applying.
  6. Navigate to default OST file: C:\Users\YourUsername\AppData\Local\Microsoft\Outlook)
  7. Rename OST file to your desired name e.g., WorkMailbox_new.ost
  8. Outlook doesn’t allow directly assigning a custom named OST file through the interface. To assign a name:
  9. Delete current Outlook profile via Control Panel> Mail> Show Profiles.
  10. Click on Add and create a new Profile and re-add your email account.
  11. Use Registry editing or management tools for advanced users to rename OST files if required.
  12. Once the new OST file is in place and Outlook opens without issues, you can enable Cached Exchange Mode back on.
  13. Launch Outlook and allow to recreate or re sync the OST file.
  14. Confirm that the new file is retained and synced properly.

Rebuilding OST File: When Renaming Isn’t Enough

  1. Clear Outlook running apps in background.
  2. Navigate to OST storage location: C:\Users\YourUsername\AppData\Local\Microsoft\Outlook
  3. Right-click on the OST file and select delete, or rename it e.g., old filename.ost.baka to keep it as backup.
  4. Outlook will no longer use this file upon restart.
  5. Open Outlook , it will automatically detect an OST file and rebuild a new one by downloading mailbox data from Exchange Server or Office 365.
  6. Depending on the mailbox size and network speed, syncing may take some time.
  7. Keep Outlook open until All folders are up to date and a message appears in the status bar.

Changed OST File Name But Still Can’t Access Its Data? Here’s the Solution

Renaming an OST file is easy but it may not resolve the problems you’re facing with your OST file. If you are having several difficulties with your OST file and want to fix them before renaming it, you should try BitRecover OST File Recovery Software. If you use this software, you can easily get all the data available in your OST file such as emails, notes, contacts, calendars, tasks, etc in a healthy way without facing an error.

The tool helps you to rename OST file in bulk while getting your OST file data and save them in 30 different formats to make it easier to access across multiple platforms. No matter what issues you are having related to your OST file, even if you don’t know what causes your OST file corruption, you can easily resolve them all just by using this tool before changing its name.

Steps Rename OST File by Fixing All Issues

Follow these steps to rename or rebuild OST file while fixing all the issues you are facing with it:
rename OST file

  1. Start the tool and add OST files or folders.
  2. Specific required folders and click Next.
  3. Select a PST format in the saving option.
  4. Select path by clicking on Browse button.
  5. Click on the Repair button to start the process.
  6. Change OST file name by navigating to its file location which you just selected.

Note: After recovering and convert OST to PST, you can import them with any name you want.

Common Errors and Troubleshooting Tips
  • Cannot Start Microsoft Outlook. The Set of Folders Cannot Be Opened.
    Solution: Delete rename OST file and relaunch Outlook to let it create a new one automatically.
  • OST File is in Use and Cannot Be Renamed or Deleted
    Solution: Open Task Manager and find Outlook
  • Outlook Keeps recreating OST file with Old Name
    Solution: Delete OST File and Let Outlook to rebuild it.
  • Synchronization Errors After Renaming
    Solution: Delete OST File and Let Outlook rebuild it.
    Permissions Denied or Access Error
  • Solution: Run File Explorer as administrator.
Best Practice for Managing OST Files
  • OST files are managed automatically by Outlook. Renaming or moving them manually can cause sync errors you’re troubleshooting to a specific issue.
  • While OST files are cached and can be rebuilt, unsynced data or custom local folders may be lost. Use Outlook Export feature to recreate PST backups file for backup and crucial emails.
  • Large OST files can degrade Outlook performance and keep file size under control by archiving old emails, deleting unnecessary folders, emptying deleted items and junk folders.
  • Outdated versions of Outlook are always prone to bugs and file corruption. Enable auto-updates to receive performance improvement and file handling fixes.
  • Store your OST file on a fast SSD drive instead of HDD. This improves read/write performance and reduces delays when opening or syncing Outlook.
  • Remove outdated or unusual mail profiles to reduce conflicts and errors. Use Control Panel> Mail> Show Profiles to manage items.
  • If you rename or relocate an OST file, keep records of the changes- especially in a shared or enterprise environment. This helps avoid confusion and support future troubleshooting.
Conclusion

We hope now you understand how you can rename OST file and in what ways you can make this process more beneficial for you. We explained several different methods to Change OST file names in Outlook 2021, 2019, 2016, 2013, 2010, 2007. And we also saw that doing it is not a big deal. But what if you are still unable to read OST file emails and items even after changing its name? For this we suggested you a software that you can use before renaming your OST file.