How to Open Corrupted OST File in Outlook without Data Loss

admin | May 25th, 2016 | Outlook

MS Outlook makes use of two data files i.e., PST and OST Files. PST file is the main storage repository of all the data stored in an Outlook account and OST file is the replica of all data stored in Exchange Server. OST file comes into use when the cached mode is enabled from Outlook, which allows Outlook user to work in offline mode and any changes made during this mode will be synchronized when connected to Exchange Server. In this content, we will be discussing about the corruption issues associated with OST file and the solution on how to open corrupted OST file in Outlook without data loss.

Reasons to make OST File Corrupt

Some of the reasons leading to the corruption of OST files are as follows:

Hardware Issues

  1. Damage in Data Storage Device
    If the OST file is stored in a storage device like hard drive, which has some bad sectors, there is high chance of causing OST file corruption.
  2. Network-related issues
    Synchronization process between OST file & Exchange Server is only possible through a network connection. Failure in network can make OST file corrupted.
  3. Power Shutdown
    Unexpected power shutdown of the system may occur when the user is trying to access the contents of OST file, which can lead to corruption of OST file.

Software Issues

  1. Malware/Virus Attack
    Any form of virus attacks can damage the Exchange OST file, making them prone to corruption. Updated Anti-virus should be used to avoid such mishaps.
  2. Synchronization Issues
    OST file can be corrupted if there is any interruption while the OST file is being synchronized with the Exchange Server.
  3. Interrupted Outlook Termination
    If Outlook is shut down abnormally when user is accessing or synchronizing the OST file, then the OST file is prone to be corrupted or damaged.
  4. Exceeding Size Limit
    Outlook has a per-defined size limit of OST file and exceeding that size may lead to slower Outlook performance and can make OST file corrupt.

How to Open Corrupted OST file in Outlook

In order to access OST Files in Outlook, we need to fix them first. Outlook provides inbuilt utility scanost.exe to repair OST files, which was replaced by scanpst.exe in MS Outlook 2010 for repair of both OST and PST files. Though the method makes the corrupted OST to healthy one, it takes unnecessary time and data are not recovered completely.

Since the above method involves loss of data, users can use a reliable third party tool, OST Recovery Software. It is used to recover data from healthy to highly corrupted OST file and saves them to healthy PST file without any kind of data loss. All the data items like emails, calendars, contacts, etc. from OST can be recovered in PST format keeping the original formatting intact. Using this approach, user can open the corrupted OST file by recovering its data in PST file.


Considering all the possible methods to recover data items from corrupt OST file, we can say that Third party tool is better option as it maintains the data integrity after conversion. The inbuilt utility may help repair the OST file but it cannot recover complete data lost due to corruption. It is advisable that users should keep their OST files healthy/UN-corrupted. However, in case of corruption, OST Converter Tool can be used for complete data recovery from OST file and accessing it in Outlook.