Problem Logging In

I'm running XP Pro and was having trouble getting my computer to work on a different network than it is usually on, so I decided I would try changing my computer's domain (normal network) over to the workgroup that the new network uses. So after restartin
g my computer and attempting to log in, Windows no longer recognizes my password. The same login name appears in the user name field, but either I am unable to log in with that name or a while ago an accout was set up for that name outside my normal domai
n with a password that I can no longer remember. Either way, I find myself unable to log in with the new workgroup. What I would like to do, is simply go back to logging in to my old domain, but that doesn't seem possible because when I'm at the login sc
reen, there is no domain selection box, even with the extra options. So if anyone could tell me a way to either change domains without logging in, or at least get a list of previously logged in user names without logging in, I would greatly appreciate it.
Thanks for your help.