When you try to change the location of the offline Outlook Data File (.ost) in Microsoft Outlook 2013 or later versions, the Browse button on the Outlook Data File Settings page is disabled.
This issue occurs because of the deprecation of the classic offline mode in Outlook 2013 or later versions. This mode is a legacy data access method for online mode connections to Microsoft Exchange Server.
To work around this problem, use one of the following methods.
Method 1: Create a new Outlook Profile and then change the location of the .ost file
Copy the existing .ost file to the new location that you want to use. If you want to create a new .ost file isntead, you can skip this step.
Open Control Panel. To do this, use one of the following procedures, as appropriate for your version of Windows.
Windows 10 and Windows 8: Press Windows Key, and then type Control Panel and then press OK.
Windows 7: Click Startand then click Control Panel.
In Control Panel, type mail to search for the Mail item, and then open it. If there are two Mail items, choose the one that is labeled with your version of Outlook, such as Microsoft Outlook 2013 or Microsoft Outlook 15 for Outlook 2013, or Microsoft Outlook 2016 or Microsoft Outlook 16 for Outlook 2016 (The screen shot for this step is listed below).
Click Show Profiles.
Click Add (The screen shot for this step is listed below).
In the Profile Name box, type the name that you want to use for the new email profile, and then click OK (The screen shot for this step is listed below).
Click Next after Outlook finds your account information (The screen shot for this step is listed below).
After Outlook finishes the setup for your account, select the Change account settings option, and then click Next (The screen shot for this step is listed below).
In the Server Settings section, click More Settings (The screen shot for this step is listed below).
On the Advanced tab, click Outlook Data File Settings (The screen shot for this step is listed below).
Click Browse, browse to the .ost file that you copied in step 1, and then click Open. If you want to create a new .ost file, browse to the location where you want to save the new .ost file, type the file name that you want to use, and then click Open. Outlook will create the new .ost file (The screen shot for this step is listed below).
Click Finish to finish the setup for your email account.
Open Control Panel, and then open the Mail.
Click Always use this profile, select the new profile that you created, and then click OK (The screen shot for this step is listed below).
Method 2: Set the ForceOSTPath registry entry to change the location of the .ost file
Note The value of the ForceOSTPath registry entry only works for a new Outlook profile.
Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:
322756 How to back up and restore the registry in Windows
Here's an easy fix: change the location of the .ost file
To fix this problem automatically, click the Download button. In the File Download dialog box, click Run or Open, and then follow the steps in the easy fix wizard.
This easy fix solution will help you set the default location of the .ost file to C:\Users\UserName\Desktop.
Firstly, you need to make sure you have “Create files / write data” Permission in the folder. Then, follow the steps in the easy fix wizard to change the default location to the folder where you want to store the .ost file.
This wizard may be in English only. However, the automatic fix also works for other language versions of Windows.
If you’re not on the computer that has the problem, save the easy fix solution to a flash drive or a CD, and then run it on the computer that has the problem.
Let me fix it myself
Easy fix 25022
To set the ForceOSTPath registry entry in order to change the location of the .ost file,follow these steps:
Click Start, click Run, type regedit in the Open box, and then click OK.
Locate and then select the following registry subkey: