Repair a 2GB Personal Folders or Offline Folders file

Outlook has no built-in way to reduce a PST or OST file that has gone over the limit. However, Microsoft provides a tool, PST2GB , which you can download to restore the file to operability. Note, however, that the utility truncates the data from between 25 and 50mb and the truncated data is not recoverable. The remaining data under 2GB should be restored. See OL: Oversized PST and OST Crop Tool for more information.

Make a backup of your PST or OST, then open the original file with the hex editor (available for download from any Windows shareware site). You'll want to remove a few characters from the middle of the file, then save it and try to run the Inbox Repair Tool (Scanpst.exe) to repair the damage you did with the hex editor. If Scanpst can repair the file, you should be able to open it Outlook again. If not, try removing some additional characters from the file.

If this process works, with any luck, you'll lose only one or two items. You may be able to recover 100% of the data by repeating the process with a new copy of the file, but removing the data from a different area.