Windows 7 PST file corruption??


I use a single PST file as my main information store between home and office. The file is 100MB and has recently been compacted. At the office, we have an Exchange Server, and at home I interface with my POP. Ultimately evertything gets filed in this PST file which I carry on removeable media in order to update whichever machine I am working on. I have recently started running the PST repair utility on this file every couple of days and it almost always detects errors. Below, I have included the output from one I ran just this afternoon. The 2-part question I have is:

1. What causes this corruption in the first place? (I have read a bit off the web and it seems that this is an accepted truth about PST files, however it seems unacceptable to me!)

2. Given the output below, the utility tells me it is "attempting" to do a lot of stuff. Are there any unrecoverable errors in this list? The output wasn't specific enough to reassure me that it fixed everything and that it encountered no un-recoverable errors. The final pop-up confimation box does actually say that the file was repaired.


Gavin Oscur

Well-Known Member

Outlook PST File might be corrupted due to the following reasons like Power Failure, Virus or other Malicious Software, Terminate Outlook Abnormally, etc.

Instead of copy/paste you can export your Outlook PST File because copy/ paste somewhere generate error.

I have a question to you that had you tried scanpst.exe (Inbox Repair Tool)? If not, then use scanpst.exe (Inbox Repair Tool) which is a free utility provided by Microsoft. But, this tool does work only for lower level corruption. After using this tool, if your PST File still remains corrupt then you have to go to any third party utility.

Thanks & Regards

  1. Exit Outlook, then click Start > Computer.
  2. Browse to <drive>:\Program Files or, if you see a Program Files (x86) folder on the same drive, browse to that instead. For example, C:\Program Files or C:\Program Files (x86).
  3. In the Search box, type Scanpst.exe.


Fantastic Member
Premium Supporter
Bear in mind that the size of your PST or OST file is often the limiting factor. The larger the Outlook data file, as with an flat-file relational database gets more complex and more difficult to keep running properly. Some customers I have do things such as compressing their PST files or even encrypting them with various 3rd party encryption programs. The absolute worst thing you can do to Outlook files is to compress or encrypt them or BOTH!! :down:

I had one Customer a number of years ago that never did any maintenance on the E-mail inbox component of Outlook (this was Outlook2003); and had never deleted an E-mail from her inbox in the 8 or 9 years she owned the computer. It was a small company running Windows Server 2000 about a dozen users on their business network. They were also running Exchange Server 2000. When I went to work on her Outlook it would take 3 or 4 hours to load up in the morning; so bad she would come in at 6am and not be able to get to read her E-mail until after 10am; over 4 hours. When I got in there to fix it, she had something like 300,000 messages in her Outlook inbox--an all-time record!! And she never was taught how to file messages by her Network Admin, and almost everyone that does anything with Exchange mail knows that you NEVER EVER should have more than 500 messages unfiled in your Inbox. You can have thousands of messages, but they have to be stored or moved into folders in the PST nav structure to keep from bogging down the Outlook Client to Exchange server sync time. If you don't do this, and the Inbox exceeds that limit; your PST file will crash, be corrupt, or freeze/hang, lose communication with the server, lose mail messages, folders, calendars, contacts, tasks, etc.

Most of these recovery tools will work on smaller files such as yours (100MB); mine here is 214MB on Oultook2016. But, when the PST file or OST file involves syncing with an Exchange server which may or may not sync other functions between client users computers and the server which includes E-mail, contacts, calendar, and tasks; as well as shared folders for each of these or all of these, these products generally do not work well. I haven't tried the specific product mentioned above in Post #4 for these types of advanced Outlook file recovery, but I've tried just about all the others out there and then some. No luck with those, lots of money spent and a lot of frustration.

If you have a simple repair, and the built in repair tool mentioned, scanpst.exe can't fix it, and you have no file compression or encryption or Exchange syncing involved, 3rd party tools may help you. But, they never worked for me and I did this for a living as an E-mail administrator.:(

If you get nowhere, there are companies that specialize in this type of software repair, I've used some with some success such as CSC (out of business I think), IBM, and Perot Systems. Since you are connecting to a business Exchange server, have you contacted your IT department to see if they can help you out? This is well outside the purview of a user to solve usually. They also may have repair tools not mentioned here, or are using high-end software vendors such as I mentioned (who are very expensive) that may already be doing this kind of work for other users in your Company that have fouled up PST files in their Outlook.. Might be worth a phone call.

Best of luck,:encouragement:


Fantastic Member
Premium Supporter
We haven't heard back from OP in 5 months; so we don't know what they tried, or if they tried anything at all. Perhaps fixed the problem using one of our suggestions, but never came back to give us the final result.



Fantastic Member
Premium Supporter
@adom: you are posting this not for the OP, but for everyone else's edification? OP hasn't responded in 6 months, and has either solved their problem via a different tool, reinstalled their Windows, or just plain gave up! Did you read my Post? These sorts of tools do NOT work on compacted PST or OST files!! The OP mentions this right in his first Post! This is usually also try when the PST/OST files are encrypted or encrypted/compacted as well. I've paid lots of money to do this, and haven't seen a solution that works.


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