Changed XP user name can't access share

I changed the user's name on a new Windows XP Pro computer to match a =
name of the old computer's user name that had permission on a network =
share. The new XP computer could not access the share. I noticed that =
only the name was changed, the user's folders were still under the =
original user name. I also found that I could still log into the XP =
computer with the original user name. Was the network user's name =
changed when the user name was changed? What name does XP use to log =
into the share, the original user name or the new user name? I finally =
deleted the user account and created a new user account with the same =
name and I was able to access the network share just fine. Apparently =
the changed user name was not the name that Xp was using to access the =
share. Is there a way to make XP log onto a share with a changed user's =
name or is it necessary to create a new user account?

Thanks,
Steve Smith