Last reviewed on March 17, 2015   —  52 Comments

While it's usually not necessary to relocate the offline cache used by an Exchange account, it is possible to move it to another folder or partition. For the most part, it only makes sense to move it if the C: drive is full.

Outlook 2013 IMAP and EAS (Outlook.com/Hotmail) ost files are moved using the ForcePSTPath key.

Moving the offline cache so its easier to back it up is generally pointless: it's an offline copy of your Exchange mailbox and it can only be opened by the account that created it. If you try to use an old cache file, Outlook will complain that it doesn't match the server mailbox. If the server fails and there is no server backup, the contents of the current, most up-to-date *.ost should be used to repopulate the server. In short, if you want a usable backup of your mailbox, export the contents to a *.pst file instead of including the *.ost in a backup file.

If you need to recover data from an orphaned ost file, I have a list of commercial recovery software listed at Convert an Offline File (.ost) to a Personal File (.pst)

With that disclaimer out of the way, if you do need to relocate the offline file, you can move it using the following steps.

If you are moving an .ost file, you need to create the ForceOSTPath registry value before adding the account to your profile.

Move the *.ost in Outlook 2010 and older

In Outlook 2010 and older, you can move the ost used by cached Exchange to another location by disabling offline mode then changing the path on the Advanced tab of the Exchange account properties.

If you want to move the ost before you create a profile, use the ForceOSTPath registry value.

Move the cached Exchange ost file in Outlook 2010 and older

  1. Open Account Settings
  2. Click More Settings (1)
  3. Deselect Use Cached mode (2) and click Apply.
  4. You can close Outlook and move the ost file now. If you want to create a new .ost file, you can skip this step.
  5. Click Outlook Data File button (3)
  6. Disable offline use (4) if Browse button is not enabled
  7. Click Browse button to select moved ost file (5)

Move the *.ost in Outlook 2013

The above method does not work with Outlook 2013. When you try to change the location of the offline file (.ost) in Outlook 2013, the Browse button is disabled.

You need to use one of two methods to move the ost file and both involve a new profile. If you are making a new profile, you can use ForceOSTPath registry key. Or you can move the .ost file and create a new profile in the Control panel, Mail applet and point it to the new location.

  1. Copy your .ost file to the new location. You can skip this step if you want to create a new .ost file.
  2. Open the Control panel, find Mail
  3. Click Show Profiles
  4. Click Add
  5. Control panel, mail dialog

  6. Type a name for your new profile, click OK
  7. Enter your username and password and let Outlook find your account information
  8. Select the Change account settings option, and then click Next
  9. Change Account Settings

  10. Click More Settings (1)
  11. move ost in Outlook 2013

  12. On the Advanced tab, click Outlook Data File Settings. (2)
  13. Click Browse (3), browse to the .ost file that you copied in step 1, and then click Open.
  14. If you want to create a new .ost file, browse to the new location, enter a filename, and then click Open. Outlook will create the new .ost file.
  15. OK your way back to the Mail profile dialog
  16. Click Always use this profile (shown in second screenshot), select the new profile that you created, and then click OK to close the dialog

Tip: You can jump to the ost location in Windows XP, Vista, or Windows 7/8 by typing or pasting this command into the address bar of Windows Explorer and pressing Enter:
%USERPROFILE%\Local Settings\Application Data\Microsoft\Outlook

 

Using ForceOSTPath to set the file location

The ForceOSTPath key is supported by Outlook 2003 and up, but applies only to new profiles (or in the case of Outlook 2010 and 2013, to new accounts in a profile).

You need to set this key before you add the account to your profile.

Open the registry editor and browse to this key (create it if it doesn't exist). Create a string value named ForceOSTPath and add the path. (You can use variables if you are using group policy to push it out to your users.)

Outlook 2016

HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook
Expandable String Value: ForceOSTPath
Value data: full path you want to use

Outlook 2013

HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Outlook
Expandable String Value: ForceOSTPath
Value data: full path you want to use

Outlook 2010

HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook
Expandable String Value: ForceOSTPath
Value data: full path you want to use

Outlook 2007

HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Outlook
Expandable String Value: ForceOSTPath
Value data: full path you want to use

Outlook 2003

HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Outlook
Expandable String Value: ForceOSTPath
Value data: full path you want to use

Common variables

Variable Typical value (May vary)
%APPDATA% C:\Users\{username}\AppData\Roaming
%LOCALAPPDATA% C:\Users\{username}\AppData\Local (default for OST files)
%USERPROFILE% C:\users\{username}
%WINDIR% C:\Windows

More Information

The steps to move IMAP, POP, Sharepoint or Internet calendar pst files are similar, but cache files used by the Outlook Connector can't be moved. Outlook 2007, 2010, and 2013 support the ForcePSTPath registry value, which changes the default *.pst path for POP3, IMAP, and SharePoint data files. See How to move the IMAP personal folder (*.pst) for more information.


Discuss in our community

Comments

  1. Ron says

    Oh, you are my hero. I was searching for this for 2 days! I had to relocate the OST file on my tablet to save my internal memory. Strugling with all the articles before Outlook 2013 I finally found this article! Thank you so very much!!

  2. John Brown says

    I've tried this multiple times and cannot get the ost file to move to my D: drive. I completely uninstalled Office and wiped the registry settings for it so I could start clean. I added the ForceOSTPath key and then created the account in Outlook. It always uses the default C: location and of course I'm unable to change it.
    When I tried the create a new profile option, the part where you say to select Outlook Data File Settings in the advance tab is not even there, so I'm pretty much stuck. I'm trying to get this ost file off my SSD drive to conserve space to no avail. NOTHING should be this difficult to move a location. I don't understand why they made it harder in 2013, I'm sort of regretting that I upgraded now.

    • Diane Poremsky says

      That tab is used with Exchange mailboxes. What type of email account are you using? Which version of Outlook?

  3. Mohamed Azher says

    I have the same problem, i am trying to configure my gmail account with outlook 2013. I tried setting ForceOSTPath but it does not work with new profiles/accounts. Also also the part where you say to select Outlook Data File Settings in the advance tab is not even there for me either.

    No matter what i do the datafile gets created in the c:

    • Diane Poremsky says

      I'll test it with Outlook.com and IMAP accounts - it *should* work but its possible they broke it in 2013.

  4. JB says

    Have you figured out anything with the people who are having trouble with IMAP and not being on Exchange. I have tried the registry change (even the automated one from MS) and it doesn't work and the setting when doing a new profile isn't there since I'm not using exchange.

    • Diane Poremsky says

      Are you trying to move the IMAP data file? You need to use the forcepstkey for all versions, including Outlook 2013.

  5. JB says

    I am trying to move the IMAP (OST) file. Do I need to set the forcePSTpath as well? I doesn't look like it is making a PST at all, just the OST in %localappdata%\microsoft\outlook. I have tried setting the forceOSTpath to no avail. If I make a new profile (or a new account, since I have 2013), it does not seem to use this setting.

    • Diane Poremsky says

      Outlook 2013 IMAP accounts use an OST but the ForcePSTPath key still controls where the IMAP data file goes. You don't need the forceostpath key if you don't have exchange, only the forcepstkey is needed for imap. you will need to remove the imap account from your profile and add it back after setting the key and restarting outlook.

  6. Lubor says

    The move does not work for me either. I have exactly the same problem as described above by Mohamed Azher. I set the ForceOSTPath. I don't see the "advanced tab" either. And the OST file is created in the "old" default location even before I perform "7.Select the Change account settings option, and then click Next".

    • Diane Poremsky says

      Are you moving an Exchange ost or IMAP? Outlook 2013 IMAP ost files are controlled by the ForcePSTPath key, not the ost key.

  7. Scott says

    I just installed Office 365 Home Premium on my computer yesterday and I have a Hotmail account that I'm trying to set up with Outlook. I have an SSD drive so I'm trying to move the OST file off of it (as I see others are trying to do). I tried doing it through the Mail applet as shown in the article but that didn't work. I also tried setting the ForceOSTPath in the registry and it didn't work either. Please let me know what else, if anything, I can try.

    Thanks,

    Scott

    • Diane Poremsky says

      If the ForceOstPath doesn't work, you'll need to use junction points. Note that forceostpath only works with accounts created after you set the key, it won't work with existing accounts.

  8. smichels62 says

    What are "junction points"? Also, I tried deleting the account before setting the ForceOSTPath then created the account.

    Thanks,

    Scott

  9. smichels62 says

    I just noticed at the top of the page where it says to use the ForcePSTPath key for Hotmail. Don't know how I missed that. I think I got confused since the Hotmail stuff gets stored in an .ost file but the name of the key to use has "PST" in its name. Something's just not quite right with that, IMO.

    Scott

    • Diane Poremsky says

      You didn't miss a thing. :) I updated the page after I verified it worked with the EAS ost. (It doesn't work with the Outlook Connector ost.) Thanks for bringing it to my attention, I checked the key and updated the pages because of your query.

  10. smichels62 says

    That's nice to know. For a minute there I was thinking maybe I'd gotten more senile or something. I knew I wasn't going insane since I did that a long time ago. Also, I saved the links you posted about Shell folders and Junction Points so I can check them out later. Might be useful, who knows.

    Thanks again,

    Scott

  11. Anon says

    None of this crap is accurate for Outlook 2013. Idk where this dumb ***** got her degree, but there's no button in the Advanced tab to change the location. This entire page is worthless.

    • Diane Poremsky says

      Normally, I let the nasty people stew for a few hours, days, or weeks as I work to help everyone else, but I will happily point out that you are wrong - there is a button on the advanced tab in Outlook 2013 -
      Advanced Tab.

      I'm going to take a wild guess and say you aren't using an Exchange mailbox (the topic of this page, as mentioned in the first line) and that is why you don't have the button on the Advanced tab. I'll make another guess that you are using an IMAP account and missed the notice in yellow that says: Outlook 2013 IMAP and EAS (Outlook.com/Hotmail) ost files are moved using the ForcePSTPath key.

      (oh, and I don't allow bad language on my website.)

  12. Vijay Arora says

    There is a slight change in Office 2013 with OST redirection in the registry key. Try below, it should definitely work for you.

    Open registry and go to below path>>

    [HKEY_CURRENT_USERSoftwareMicrosoftOffice15.0OutlookOST]

    Create new string value >> ForceOSTPath
    Double click on it and put desired path under "Value Data"

    Create outlook profile and check the location you have given under "Value Data"

    This worked fine for me.

    Vijay

    • Diane Poremsky says

      Sorry, that key is not correct, it won't work in the OST path. It works in either HKCU\Software\Microsoft\Office\15.0\Outlook or HKCU\Software\Policies\Microsoft\Office\15.0\Outlook

    • Vijay Arora says

      Diane when you run outlook 2013 for the first time it create OST under HKCUSoftwareMicrosoftOffice15.0Outlook

      I have created Sting Value as ForceOSTPath and OST redirection is working fine for me.

      HKEY_CURRENT_USERSoftwareMicrosoftOffice15.0OutlookOST

    • Diane Poremsky says

      The OST folder is only created if Outlook needs to create it, it's not created by default. It's used by some keys, such as NoOST, but is only created when needed. The ForceOSTPath (and ForcePSTPath) key does not go under OST, it can either be under HKCU\Software\Microsoft\Office\15.0\Outlook or as a Group policy at HKCU\Software\Policies\Microsoft\Office\15.0\Outlook
      https://support.microsoft.com/kb/2752583

  13. D says

    Will this action create a new *.ost file in the new location, which will include everything from the old *.ost file + plus new stuff that will be added, while the old *.ost file will be discontinued (for lack of a better word)? Right

    I want to make sure, that in the new location there will be all the emails from the ost file from the old location

    • Diane Poremsky says

      With an Exchange ost, everything is stored on the server, so yes, everything will resync.

    • Diane Poremsky says

      Which account type are the ost files for? Did you create the accounts in Outlook AFTER setting the key?

  14. Jim Watson says

    One is an Exchange account (Hotmail), the other is IMAP (Gmail).
    I deleted both accounts, set up the keys, then recreated the accounts.
    Also tried junction points and symbolic links but Outlook apparently ignored those.
    What I find really frustrating is that I have just reinstalled Windows 8.
    In the previous install I had managed to move both PST and OST files without any problem.
    The wonders of Windows. :(

    • Diane Poremsky says

      The ForcePSTPath should work for both of those account types, provided you remove the account from the profile and recreate the account.

  15. Jim Watson says

    Having tried ForcePSTPATH, ForceOSTPATH, symbolic links, directory junctions, etc etc, I have now decided to give up before my head explodes.

    • Diane Poremsky says

      I have no idea why its not working - it should - and exploding heads aren't good. :)

    • Jim Watson says

      What really burns me is the fact that prior to the reinstall I had no problem moving the darned things.

      :(

    • Diane Poremsky says

      It *should* work - I have absolutely no idea why its not working now. The folder path your are using does exist, and have the right permissions, correct? (If it's on a drive that wasn't reformatted and you reinstalled windows, permissions could be the problem.)

    • Jim Watson says

      Checked the permissions, could see nothing wrong, but to be sure I opened up the target volume and folders to full control by any user.
      Still no joy.
      Is there perhaps an event log which might give a clue as to what's gpoing on?

  16. Cyn says

    Not techie, but followed your directions and when I went to enter the profile it said the path to the data file was invalid. I know it's right because I navigated to it about a million times before I found your article. Hotmail, Outlook 2013, Windows 8.x?

    • Diane Poremsky says

      This is with a Hotmail account? You can't move the ost, you need to use the forcepstpath key (yes, 'force pst', not 'force ost') to move it. note that unless you have a small drive and need to move it to a larger one, there is little reason to move it as backups aren't usable - an ost can only be opened by the account that created it.

      Use the forcepstpsth registry key and then remove the account from your profile and add it back.
      http://www.slipstick.com/outlook/config/how-to-move-the-imap-personal-folder-pst/

  17. zachiP says

    can someone help? i have an existing ost and i want to import pst but to use it as default data file - i know you can do that via account setting (set as defualt). but how can i do that without GUI involved -->. registry or COM object?

    • Diane Poremsky says

      A PRF can set the default data file. The registry key that sets the default varies with each profile, so its difficult to do using code or via the registry. I'm not aware of any utilities that will do it.

  18. Shailendra says

    Did not help as I never got the option to change the OST file path under settings. Browse button is disabled by default and taking default user location for OST file.

    • Diane Poremsky says

      Did you disable cached mode first? The button is disabled if cached mode is enabled.

  19. Keith M says

    I found a way to move existing OST files without rebuilding profiles. I just moved over 600 OSTs for my users without a single profile needing to be rebuilt.

    1. Move the OST to the new location
    2. Break the path to the old location. I used a symbolic link command that pointed to a bogus OST destination. You could delete the directory that the old OST used to live in, but that might cause other issues
    3. Start Outlook. It will complain that it didn’t see the OST and will prompt you to browse to it. At that point, you can repoint Outlook to the OST file that is in the new location.

    If you are a network admin, trying to move OSTs to a new location, here is what I did:
    - Created a list of all OST files that needed to be moved. Converted that list into a .bat file that did two things:
    o Move the ost from its current location, to its new location
    o Create a symbolic link in the old location that points to a non-existing location
    Here is an example of what my .bat file looked like:
    move u:\AmandaC\AmandaC.ost o:\AmandaC
    mklink "u:\AmandaC\AmandaC.ost" “put_bogus_path_here\AmandaC.ost"
    - Created a GPO that sets Outlook to use Offline Cache and sets the destination folder (apply to all users ahead of time. It won’t do anything on pre-existing Outlook profiles)
    - Created a GPO that runs a script on login. I used WinBatch to create the script, which does the following:
    o Check to see if the file “ost.txt” exists in the user’s home directory. If so, exit (the script already ran for this user)
    o If ost.txt doesn’t exist, open outlook. Wait for the Data File location error to appear and click the browse button. The default browse location will be what you set in the GPO above.
    o Select the OST in the browse list. OK, OK,…
    o Copy ost.txt to the user’s home directory so the script won’t run again for them
    o Outlook will open using the OST file in the new location, using the same profile, with any PSTs that were attached, etc… Nothing is lost!

  20. bob says

    To those people who have trouble relocating gmail etc ost's, it could be that the location is being set in group policy. If it is, it will override your attempts to relocate it.

    check HKCU\Software\Policies\Microsoft\Office\15.0\Outlook

    for the forcePST and forceOST keys. if they're there, change them and recreate your account in outlook before the group policy has a chance to reapply.

  21. zack says

    I hope I did not miss this in the original post, but will this work if you are moving the OST to a new computer? So far the only thing that has seemed to work is creating a new user profile on the new PC and letting exchange rebuild the ost file, which will kill a WAN network.

    • Diane PoremskyDiane Poremsky says

      Try this: Copy the old ost file. Configure the Outlook account and start Outlook. When it shows 'Connected to Exchange Server', close Outlook. Make sure that it is not open in the notification tray. Find the new ost file and overwrite it with the copy. The names must be the same! Re-start Outlook.

  22. zack says

    Thanks Diane, we will give that a try. Hope it works because we have about 200 PCs that we are going to be replacing soon.

    Thanks again for all the help you provide to the Exchange community. I know I can usually find an answer here when faced with an exchange/outlook problem.

  23. Amer says

    Hi Diane. I am using Office 365 Home Premium and I have ten Gmail accounts that I am viewing on Outlook in an IMAP setting. I don't have any other emails accounts other than with Gmail. I am running out of space on my C: drive and would like all Outlook related data moved to a new drive on my computer. This was the case previously when I was using Outlook 2010, but after updating, I seem to have taken a turn for the worse on my C: drive. I have spent over 6 hours with various Microsoft technical support people and they have just wasted my time. Please advise if it is possible to move all Outlook data to another drive with IMAP settings for Gmail accounts.

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