Is there any way to "restore" a .pst (Outlook Personal Folder) or .ost (Offline Folder file)?

I have Microsoft Outlook 2007 installed and use IMAP for all my mail accounts. When I updated to Windows 7 I had to reinstall Outlook and thus download all the headers again. I ended up downloading everything again, but I would want to prevent this in the future.

Is there a way to import my Microsoft Office Outlook Personal Folders (.pst) or Offline Folder (.ost) files into the new installation, so I don't have to download all the headers again?

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Edit: I checked the extension of the files in my current Outlook folder, which are .pst files, is it possible Outlook changed them to .ost files when I was messing around with my Outlook settings? I've changed my question to import .pst or .ost.

Edit2: I tried exactly that and even made sure they had the correct name, but then Outlook would crash on me. I guess there is more to it than just the file names... I also tried some programs to restore .ost files, which actually managed to get files out if it, but also tried to empty my wallet... I'm hoping for a kick-ass hacky way to get it working anyway!

Answer

I have had success with two different methods:

Method A

1. Save your pst/ost files (copy to a safe place via windows explorer)


2. Re-install Outlook and set up the account, but prevent it from downloading anything.


3. Note the location of the pst/ost files for the new Outlook installation


4. Close Outlook


5. Via explorer, replace the new installation's pst/ost files with your saved ones


6. 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