Simple Win XP "connect as" question

[JimKiler]

I have two Win XP Pro PC's and for some reason PC A will only connect to PC B as Guest. I even try to map network drive and there is an option to connect as a different user which i do and it asks for the username and password but then it asks for a password for guest right after that. What am I missing?

I have tried two different admin usernames and neither will work. Is there an option somewhere I am missing.