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This morning I reformatted and installed Windows 7. After installing Office 2007, I imported my Outlook data from my dutifully made backup PST file. The only problem seems to be that now I have duplicates of everything that had been backed up. New items arriving are not being duplicated.

I have the data backed up, so I'm willing to wipe the slate clean with Outlook and start over (the install, not my data), but I'd rather not do it again, and again, and again, until I finally get it right; so I'm curious what the best path to take is.

I'm on a Windows domain, using my domain email account. I think (but I'm not positive) that the duplicates were synchronized down from the exchange server after I imported by backup.

It seems to me that I should be able to just clear everything out, setup my account again, and let the exchange sync bring everything down. If that's the case, how do I properly clear out the data from my current install? If that's not the case, what's the best install-&-restore path?

Alternatively, is there a decent, reliable, and free way to delete duplicates? I tried this method from Microsoft, but my modification date/times match exactly.

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up vote 1 down vote accepted

The quick and dirty way to do this would be to simply setup your accounts and let Outlook create a new PST. Once done close Outlook and replace the PST with the backup PST and reopen Outlook. I did this a few times in the past when having to manage reformatting machines in a corporate environment and keeping PST's.

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Take a look at Outlook Duplicate Remover. It worked well for me the one time I tried it.

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This worked flawlessly for me! In my case I had duplicate entries due changing my phone and messing up with Nokia's Mail for Exchange. All my calendar entries were duplicated, but are no more! Thank you very much! – Janne Pikkarainen Sep 2 '10 at 10:09

Sounds like you're using Exchange. If that's the case, then there was no need to re-import from your backed up PST file. (Since everything in an exchange connected PST is stored on the server)

I would make another backup of your PST as it is now (for safety reasons) and ask your administrator to purge and recreate your mailbox. Then, reconnect to it, and import your first backup file again - this should bring your items back into the new exchange mailbox without duplication.

I'm not responsible for any loss or damages you or anyone else may incur by using this solution, it's up to you to ensure you have a reliable backup of your email. :)

Of course, none of this applies if you're not using Exchange, and my only solution is to delete the profile and reimport your backed up PST. (again, standard backup warnings apply)

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