multiple folders in outlook

[matanzas]

I have a client who found (after returning from holiday) that Outlook had 3 sets of mail folders not all of which were the same (when she left for a week there was only one set). The machine is not a shared workstation although there are two profiles on it as she is using it while another person is on maternity leave. I cannot imagine that they appeared on their own altough I could be tricked (I suspect someone accessed the machine for another purpose).

Queston is, can I drag the messages in the additional folders to the original set and delete the extras

or

do I have to back up the folders, uninstall/reinstall Outlook and restore the back up correctly?

Thanks in advance