Summary: In this post, we explain how OST file is different from PST file and what are some situations in which you need to move an OST file. We also share some methods for moving an OST file to your desired location.

Outlook can save mailbox data in two formats- PST and OST. The former is a portable format that’s used for creating mailbox backups, while the latter is an offline copy of your Exchange mailbox which is regularly synced with your online mailbox.

You generally don’t need to move an OST file as it’s simply a replica of your Exchange mailbox and can be easily recreated in the new location. However, in some situations, you may need to move the OST file. The most common scenario is when the OST file becomes oversized and fills a hard drive partition (which is usually C: drive). In this scenario, you need to move the OST file to a new location that has ample free space.

The following are three main ways you can move OST file:

  1. Workaround Solution That Uses a PDF File


This solution isn’t recommended if you want to move an old OST file whose replicate mailbox isn’t available online, and hence can’t be recreated by connecting to your Exchange mailbox. This is because this method can potentially damage your address book. However, it’s also a simple and quick method and you can use it if want to move an up-to-date OST file that can be recreated in case something goes wrong.

To use PDF file method, take these steps:

  1. Close Outlook.
  2. Press Windows Key + R to launch Run tool.
  3. Enter %LOCALAPPDATA%\Microsoft\Outlook in the text field and click OK to go the OST file location.
  4. Copy the OST file to the new location.
  5. Move any unwanted PDF file to the old OST location.
  6. Copy the OST file name and rename the PDF file with the same name. Make sure that you also change the extension from .pdf to .ost. This will make the PDF file look like it’s an OST file.
  7. Run Outlook. Outlook will throw an error saying that the file is not an Outlook data file.

  8. Click OK and browse to the original OST file that you copied to a new location.

  9. Click OK.

  10. Setting OST File Location by Using ForceOSTPath

You can safely change OST file location by using ForceOST registry key. However, you need to meet either of these conditions to use this method:

• Use the method before you add your mailbox account to your Outlook profile


• Removing your account first and add it back to Outlook after using the method

To apply the ForceOSTPath registry key method, follow these steps:

  1. Open Registry Editor by following these steps:

o Press Windows Key + R. o Enter “Regedit” (without quotes) in the search field. o Click OK.

  1. Locate the Outlook key for your product (refer to the list below).
  2. Right-click the Outlook folder, select New, and then select Expandable String Value.

  3. Enter ForceOSTPath as the name of the value.

  4. Right-click ForceOSTPath and select Modify.

  5. Enter the new path of the OST file into this field and select Enter.

Outlook Version Outlook Key Location

Outlook 2019 HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook

Outlook 2016 HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook

Outlook 2013 HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Outlook

Outlook 2010 HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook

Outlook 2007 HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Outlook

Outlook 2003 HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Outlook

If this method doesn’t work, you can use this method:

  1. Recreating OST File on a New Location

Rather than actually moving an OST file to a new location, you can simply delete the OST file and recreate the file on the desired location. As we know, OST file is merely a replica of your Exchange mailbox, and Outlook can create this file as many times as required by connecting to your Exchange mailbox.

By default, OST file is stored in either of the following locations:

• C: \Users\AppData\Local\Microsoft\Outlook • C: \Documents and Settings\Local Settings\Application Data\Microsoft\Outlook

You can create a new OST file by first deleting the existing OST file, and then recreating the OST file in a new location.

Follow these steps to delete the OST file:

  1. Press Windows Key + R to launch the Run tool.
  2. Enter %LOCALAPPDATA%\Microsoft\Outlook in the text field and click OK. This will take you to the OST file location.


Launch Outlook and go to File > Account Settings > Account Settings > Data Files. You can find the location of the OST file here.

  1. Delete the OST file by selecting the file and pressing the delete button.

Note: If you want to use the same OST file in the new location, then instead of deleting the OST file, move the file to the desired new location.

Follow these steps to recreate the OST file:

  1. Launch Outlook and click the File tab.
  2. Click Info and then click Account Settings.
  3. Select Account Settings again. Account Settings window will open.

  4. Under Email tab, select Exchange email account.

  5. Click Remove and then click Yes.

  6. Click New to open Outlook login window.

  7. Enter your username and password to reconnect to your Exchange account.

  8. As you setup your Exchange account, select Change account settings and click Next.

  9. Click More Settings.

  10. Under Advanced tab, click Outlook Data File Settings.

  11. Click Browse. Go to the location where you want to recreate a new OST file, enter OST file name, and click Open. If you want to use the old OST file, go to file’s location, select the file, and click open.

  12. Complete account setup.

Want to Move OST File to a Different System?

The methods discussed so far apply to scenarios in which you want to move OST file on a different location but on the same system. If you want to move an OST file to a different computer, then you can’t do that before converting OST into PST first. This is because OST files aren’t portable like PST files.

OST files are linked to the accounts they are created with, which is why you can’t open an OST file on an Outlook that’s set up with a different account. A PST file, on the other hand, is a portable Outlook data file that can be opened with any Outlook program.

If you want to transfer an OST file on a different computer, then you can use an OST to PST converter to convert the file in a few simple steps. You can use Stellar Converter for OST to convert multiple OST files, move large OST files without data loss, and convert OST files that are encrypted.


Moving an OST file isn’t as simple as moving a PST file. However, the above methods can help you accomplish the task with ease. Of course, if you want to make the OST file portable to access it on any system that has Outlook, you need to use OST to PST converter tool.Free Download OST to PST converter

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