Windows Mail was designed to directly import messages from an OE6 mailstore using
the same procedure as OE6 (in fact Windows Mail is just the next version of OE6).
Do you have multiple OE6 Identities on your Me computer?
Are you sure you copied the right folders? Have a look at Step1A in this MS KB article
to find the message store: http://support.microsoft.com/kb/270670/
My guess would be that there is some problem with what you copied onto your flash
drive. I would suggest that you delete the folders on the flash drive that have
the OE6 mailstore from your Me computer and then try again. Be sure to have OE6
on the Me computer closed/shut down before doing the copy.