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Summary: Corruption of OST files can interrupt your workflow as you will not be able to access your mails. This error can bring heavy damages to the organization that works largely using Outlook, so it’s essential to find effective ways to fix the issue. This article highlights the OST file corruption issue & suggests viable solutions to fix it. However, before processing repair you must view your OST file data using salient Kernel OST Viewer tool easily.

OST files are the offline storage folders provided by Microsoft to save user information and email data in offline mode (Cached Exchange Mode). An OST file carries the actual copy of mailbox data on the Exchange Server. When you are not connected with the Exchange server, you can access that offline files if you have saved them as OST files. The benefit of the OSTfile is that it facilitates offline working. You can easily save your data in OST files and use them while you are not connected tothe Exchange server.

How to fix OST file issues?

OST files can become corrupt and inaccessible due to various software and hardware issues. In normal situations, when the file is available on Exchange Server, you can easily recreate the OST file just by deleting the OST file from its location. Exchange Server will automatically create a new OST file with all the original data. Also, you can try to repair the Outlook profile or run Outlook in Safe mode to access the OST file data. However, there are situations when you are left with an OST file only which will require repair if gets corrupted. During the process of fixing your OST file you should check the synchronization between OST & Exchange as it can affect your migration. You need to repair the OST files to open them in such situations.

There are 3 effective ways to repair & view corrupted OST files; we are enlisting them below:

  1. Scanost.exe
  2. Scanpst.exe
  3. Kernel OST viewer

1) Scanost.exe

Scanost.exe was available with the earlier versions of Outlook and enables you to open & view severly corrupted and damaged OST files. This utility could repair those corrupted OST files too. This utility is also known as OST Integrity Check Tool because it checks & fix all errors with maintained data integrity.

Scanost is located can be found inside your system in MS Office installation folder at Drive:\Program Files\Microsoft Office\Office version.

How to repair OST using Scanost.exe?

Proceeding with the manual tool of scanost.exe in your system can provide positive results to the users. It requires a hierarchical knowledge to perform this activity, so we have mentioned step by step guide below:

  1. Find the scanost.exe in your system’s Drive:\Program Files\Microsoft Office\Office version.
  2. Open Scanost.exe & configure profile as per your Outlook.
  3. Choose to connect online or offline.
  4. Now, select the OST file your want to repair & click on Repair errors.
  5. Click on Start Scan to begin the scanning process.

Advantages of Scanost.exe

  • Easily scans and checks the entire OST file data.
  • Easily finds any conflict between server and client.
  • It ensures harmony between server and client.
  • Find scan log files in the folder of Deleted items of MS Outlook.

Disadvantages of Scanost.exe

  • Doesn’t maintain data integrity.
  • Not capable enough to repair or recover damaged OST files.
  • Supports only Outlook version 2007 & previous versions


2) Scanpst.exe

Scanpst.exe is widely known as a Inbox Repair tool by Microsoft that helps to repair and OST and PST files both. This tool allows you to repair large corrupted and damaged OST files. User can find Scanpst is located in your system inside MS Office installation folder which is easily accessible and is usable for MS outlook data files.

Advantages of Scanpst.exe

  • Repairs corrupted OST and PST files.
  • Recover corrupted Outlook data.
  • It is a free tool provided by Microsoft.
  • Support all versions of MS Outlook..

Disadvantages of Scanpst.exe

  • Cannot repair OST and PST files larger than 2GB
  • Difference of files & scanpst.exe location in the system.
  • Unknown security restriction cancelling scanpst launch.
  • Need to run this utility many times to repair files


3) Kernel OST Viewer

Reviewing your OST file data is a must to do task as it assures the integrity of your data, so that you can go ahead with migration. Using ordinary ways to view Ost content can fails to run or show unloaded data, so it’s suggested to use tool with specialized expertise. Kernel OST viewer is a free tool to open and view corrupted as well as damaged OST files. This tool effortlessly opens and views damaged OST files. This tool is easy to use because it has a user-friendly graphical user interface. This utility can open OST files without the need for the original profile. You just have to select the damaged file, and then this tool opens it instantly.

Advantages of Kernel OST Viewer

  • A user-friendly interface helps you to work efficiently.
  • Generate file analysis report to analyze OST file data.
  • Open healthy as well as damaged OST files.
  • Open OST files without the original Outlook profile
  • Compatible with all MS Outlook, MS Exchange, and Windows OS versions.

Due to the above advantages, there might be many who would think of using the Kernel OST Viewer. The tool can be used following these simple steps:

  1. After launching the software, browse and select an OST file to view its content.

    Note: you may choose between “Open Single File” and “Open Multiple File(s).
  2. Read the Process Information
    Process Information
  3. Select a folder from the folder list and then choose the OST file OST file items (s) you want to view
    Select a folder from the folder list
  4. If you want to generate a File Analysis Report, click on one of the report types on the task pane.
    generate a File Analysis Report
  5. Select the required folders and press click on the Analyze option.
    Select the required folders and press Analyze
  6. When the search is over, you will see the notification window with results:
  7. Click Ok, and then the reports are displayed in the next window:
    Press Ok

Note: The other three reports can be generated similarly.


Fixing your OST file consists of a hierarchical process which includes issue analyzing, finding probable solutions, and reviewing data contents before migrating, as we discussed above. Above we have partially discussed about the OST file corruption and how to repair using manual methods. Also, it’s evident to opt for a specialized tool like Kernel OST Viewer to view your OST file data to verify the data quality which is not effective through manual ways or ordinary tools.

Kernel for OST to PST
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