Updated pst file annoying message

[niemda]

When I played with Outlook 2010 it converted my *.pst files to 'new' format.
Outlook 2007 works with it, but keeps showing annoying message at every
launch. Is there any way to disable that message or convert *.pst in 'old'
format?

 

[Russ Valentine]

Your post does not fit with reality. New versions of Outlook cannot and will
not change the format of your previous PST file. Provide the evidence that
made you think otherwise. Your post contains no information. You didn't even
provide the error message.
Surely you didn't play with a beta without backing up your data first. Just
use your backup file.