File extension OST (.OST) information

Windows cannot open OST files?

If Windows is unable to open file extension .OST you may have registry related errors or may not have the appropriate program installed. We strongly recommend that you run a free registry scan.

Appropriate program:

The .OST file extension identifies an Outlook Offline Folder File which may sometimes also be called an Exchange Offline File. This file will be used to cache your e-mails offline locally on your computer when connected to a corporate e-mail server.. Incorrect associations are the cause of many file extension errors. Scan your system to prevent, identify and repair OST file extension association errors.


  • Performance: To optimize memory and CPU usage for OST files run a free performance scan.
  • Stability: Fix OST errors to make your system and applications more stable.
  • Drivers: Scan your PC for the outdated drivers which lead to system errors and slowdowns.

You are currently viewing the detail page for ABF file extension. This page contains a detailed description of the ABF file type, software tools to help resolve file association errors in the Windows registry together with relevant system utility applications and other related information.