In Exchange environments, Outlook users face OST file corruption issues very often. To get rid of OST issues, they can either use the free Inbox Repair Tool or a third-party OST recovery software. Both the ways are efficient enough to repair and recover corrupt OST files. However, due to some technical limitations of the free tool, many users prefer third-party tools for OST recovery.

Reasons of OST file corruption

The most common reasons of OST corruption are:

  • Exchange Server failure
  • Virus attacks
  • Abrupt Outlook exit
  • Interrupted network connection
  • Data synchronization issues
  • Unexpected system shutdowns

Common OST file error messages

When OST files become inaccessible, you cannot access your mailbox data until these files are repaired. If you try to access corrupt OST files, you might get error messages. One of the most common error messages you may get is:

Cannot open your default email folders. The file xxxx.ost is not an offline folder file.

You can get several other error messages too. And the error messages are directly related to the reason of the corruption.

How to repair OST files using the Inbox Repair tool

You can repair corrupt OST files using the free Inbox Repair Tool (Scanpst.exe). The OST to PST converter tool is quite useful in resolving minor OST/PST file corruption issues.

Before starting the tool, exit Outlook entirely.

    1. Click Windows Explorer > Drive C > Program Files > Microsoft Office > Office (version) > scanpst.exe.
    2. When the Scanpst.exe is open, click the Browse button and select the corrupted OST file from its location and click The OST file will be scanned now, and the progress can be seen on the progress bar.
    3. Once the scanning is complete, a small dialogue box will pop up with the error details. Click Repair. After repairing the OST file, the tool displays a confirmation message.


However, this method may not be successful in all situations. And if this method fails, you need to use a professional tool like OST2PST.exe to repair the OST file.

Limitations of manual OST file repair

The Inbox Repair Tool (scanpst.exe) has many limitations:

  • It cannot repair large size OST file.
  • It does not guarantee for full repair.
  • The process is complex for non-technical users.

Complete OST Recovery using user-friendly tools

OST2PST.exe is a complete OST recovery tool. It scans the damaged OST file and recovers its items without damaging their integrity. And you can operate it on your own without any technical assistance.

  1. Open exe. In the Source File Selectionwizard, click the Browse button to select the corrupted OST file (you can click the Search button to search and find the OST file on system) and then click Next.Note:You can choose more than one OST file using the Convert Multiple File(s) option.
  2. The page will now show you the process Information; click on Finish. The scanning process starts.
  3. After the OST file scan, all the data will be shown on the preview pane. Select the required folders and then click Save.
  4. Choose the required file saving format (here, PST is selected) and click Next.
  5. You can apply filters (Subject, To, From, Folder Name, Item Type, & Date range) before saving the data; click Next.
  6. Choose the required options (for PST split, prefix addition, saving path, & saving preferences) and click Finish.

Now the OST2PST.exe saves the recovered data to the PST file.


When an OST file gets corrupted, users will not be able to access their emails. To fix OST file issues, they can try Scanpst.exe if they are technical good. And they can try OST2PST.exe if they want to recover the OST data more efficiently and smoothly.