How to Fix Inaccessible OST Files

sync_problems_in_outlookMicrosoft Outlook users come across OST and PST files often. When PST files are accessed daily, OST is not used so often but serves good purpose. Offline Storage Table (OST) files allow you to work offline and also serve as backup files as they are an exact local copy of your Exchange mailbox. However, OST files are criticized for susceptibility to corruption and errors. In such cases, there are a few options such as OST integrity check tool and Scan OST (scanost.exe) program available to get you back your valuable data.

Starting with the newer Outlook versions, Outlook 2010 and ahead, the Offline Folders file (.ost) integrity check tool and Scan OST (scanost.exe) are gone. So, if you face OS related issues such as such as minor mailbox synchronization issues or missing items, what is to be done?


You can easily delete the existing OST and create a new one. However, if you have been working offline and the OST file got corrupted before synchronization with Exchange server, you won’t be able to have the complete data stored in that OST file. You need to repair the existing OST file and here is where OST Integrity Check tool and Scan OST helped. You need to convert the OST into PST format to accessing data. Few following methods can be used to solve the problem.


Method 1: Export to PST

Exporting is not the solution but while converting an OST to a PST, exporting serves as a quick and easy way to move all content from the OST to a PST or even just the calendar and contacts.


Method 2: Using Scan PST

You can export the OST contents to a PST file as a backup. The Import and Export option in Outlook 2010 can be used for this purpose. Exporting into PST saves a backup of your OST, including latest changes made even after the last synchronization. Then you run scanpst.exe against your OST file. If ScanPST exhibits errors, you should allow the utility attempt to repair them.


Method 3: Move the items to a new PST

If importing or Scan PST doesn’t work, create a new PST in your profile and move the OST items into PST file. This method will preserve custom views and forms published to folder. While dragging default folders, such as Inbox, Calendar, and Contacts, Outlook displays a message that you can’t move default folders. The contents will be copied instead, with new folder named as Inbox (1), Calendar (1), etc. Simple synchronization issues may be resolved bur this method may not work when OST file is badly corrupted.

Method 4: Create new OST

If the OST file isn’t reparable by Scan OST or by Scan PST after conversion into PST, you can only recreate a new OST file. Recreate a new OST file when Exchange Server is available again, and then import the previously created PST content back into the mailbox. During the import, select the option to exclude duplicate items; so only the contents that were generated after the last mailbox synchronization and before the PST export was performed will be imported.

Method 5: Use OST to PST tool

All the above methods provide help but do not assure recovery. It might or might not work depending upon the situation or damage level. The best choice is to resort to a third party OST to PST converter to find an easy answer. They can easily convert OST files into PST excluding all errors within the file.

Kernel for OST to PST conversion is an excellent utility to easily migrate OST data into PST and access from any Outlook version. A free trial version is also available to evaluate the software prior making any purchase.