An old problem in a new dress: 'This 2010 outlook.pst file is not a valid data file'


  • Like a number of other users in the past I came across the problem of Outlook 2010 not recognizing a real normal data file.

    This is my situation:

    1. I ran Outlook 2010 on my AcerLaptop till I had to dump that device due to various hardware problems. Before dumping I copied the outlook.pst file and copied it temporarily to my AcerNetbook. It worked fine. On both machines I ran Windows7-64bit Home Premium with Outlook 2010 Professional Plus.

    2. I bought a new PC and am in the lengthy process of installing all my applications. Installed again Windows7-64bit Home Premium with Outlook 2010 Professional Plus, same as on my two other machines. Copied the normally working outlook.pst file from my AcerNetbook to my NewPC. Got the notorious message 'Not a valid data file'.

    3. After a lot of searching I found a helpful hint: check if the file perhaps is read-only. I checked. It was. Strange, because on the AcerNetbook it was NOT read-only. Anyhow, I removed the read-only block. Also I saw it had an attribute 'archive'. Removed that as well.

    4. The file was still not recognized as valid. After new searches I ran SCANPST.EXE which found errors and 'repaired' them. Then the outlook.pst file SEEMED to be valid, but not: the Inbox was completely empty (there should be 7000+ mails), there were 14 draft mails (should be just 1) etc. In other words: the file had not been repaired, but was (further?) corrupted. After about 30 seconds Outlook stopped completely. Restarting had the same result: 30 seconds of exposure, then shut down again.

    5. The corrupted outlook.pst file could not be deleted. C:\windows\syswow64\searchprotocolhost.exe kept it locked until I could finally kill that process with unlocker.exe and delete the outlook.pst file and replace it by a brandnew completely empty one. Then Outlook worked fine - but... without my data!

    6. Therefor my question: How to get them from my AcerNetbook (where they still work fine) to my NewPC (which has the same OS & Office version)?

    Thanks for your help.

    By the way: have mercy with me - in spite of the title of this forum I am NOT a PRO at all! So be simple with your help instructions, please!

    Sunday, June 24, 2012 5:00 PM


  • What method of copying over the file did you use?
    The fact that it had the Read Only attribute suggests that you used a CD or DVD. In that case it could very well be that it was a burned with errors. Try transfering it over the network via a network share or use an external disk instead.

    After the transfer to your PC, you should be able to open it directly in Outlook via File-> Open-> Open Outlook Data File

    If you are still having issues, you'll have to post what was being logged to the Event Viewer regarding this crash.

    The Archive attribute is used by Windows Backup and doesn't play a role in this matter.
    That the file was still locked by searchprotocolhost.exe is because the file had not yet been fully indexed yet and Outlook had not been closed properly (and inform the search indexer to stop indexing and release the lock from the file).

    For future posts, you can find the non-pro Outlook forums on Microsoft Answers;

    Robert Sparnaaij [MVP-Outlook]
    Outlook guides and more:
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    Sunday, June 24, 2012 5:36 PM