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It is not possible, as I understand it, to open a .pst file that is on read only media. This is a side effect of how Outlook works.

Leo, I have about 8 to 10 GB of old archived .pst files that I would like online just for reference. The problem is that Outlook seems to want to open and/or rewrite these files every time I open the program whether or not the content of those .pst's really changes. As a result, my image backup software picks up the changed disk sectors and bloats my incrementals every day. Is there a solution or a workaround?

In this excerpt from Answercast #22, I offer a solution for backing up archived .pst files that will keep Outlook from opening them.

Is there a solution?

The short answer is no, not that I'm aware of.

The workaround you might consider would be to throw those .pst files on a different drive that's not backed up. So that they become separate from your backup collection.

That's what I happen to do. And the reason I know this is because I experience exactly the same thing.

Move the archive files

I actually have my .pst files out on a storage device on my network. Even accessing them remotely touches the file in such a way that it appears to have been updated: the file actually has changed. This is a side effect (as I understand it) of the way that Outlook works. It actually updates information in the file, even if all you do is look at it. So much so... that it is not possible, as I understand it, to open a .pst file that is on read-only media.

So, if you have a .pst file on a read-only fileshare or you write a .pst file to a CD- or DVD-ROM, then you can't actually open it from that media. You have to copy to your hard disk before Outlook will actually open the file.

It's unfortunate. I'm not aware of a way to open the file read-only. I wish there were one. I would use it myself. So, like I said, the best solution that I can really think of is to just move the archive .pst files to a different drive that is not part of your backup.

Article C5407 - May 31, 2012 « »

Leo Leo A. Notenboom has been playing with computers since he was required to take a programming class in 1976. An 18 year career as a programmer at Microsoft soon followed. After "retiring" in 2001, Leo started Ask Leo! in 2003 as a place for answers to common computer and technical questions. More about Leo.

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1 Comment
Joe Vance
June 1, 2012 8:34 AM

I too wanted to open an Outlook PST file without having to import it from my backups. After a little searching I found a free appl that allows you to view PST files:

I found it works quite well.

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