Is there any way to "restore" a .pst (Outlook Personal Folder) or .ost (Offline Folder file)?
I have had success with two different methods:
Method A
- Save your pst/ost files (copy to a safe place via windows explorer)
- Re-install Outlook and set up the account, but prevent it from downloading anything.
- Note the location of the pst/ost files for the new Outlook installation
- Close Outlook
- Via explorer, replace the new installation's pst/ost files with your saved ones
- Restart Outlook
Method B: Also I have used the previously mentioned Outlook import feature:
- File > Import and Export > Import from another program or file > Personal Folder File (.pst) > locate PST/OST > Import
As for the difference between PST and OST files:
- OST files cache the files from the exchange server; they are "copies"
- PST files exist only on one computer; they are not stored on the Exchange server