After upgrading to Windows XP, I cannot switch
identities. I have my main identity, the others are
listed there but I can't switch to them. I just get the
main identity again. So, I deleted one, and created it
again, to try to start from scratch, and it still won't
switch to it. When I try to create that new identity
again, without deleting it first, it says that the name
is already in use. I can't begin to put my old emails in
there because I can't get to the individual identities.
Any help would be greatly appreciated!

Found the answer in the Knowledge Base! Thank you to all
the people who patiently answer questions here - it makes
things so much less stressful to know that there is a
place to go!