If you're trying to get it to log on automatically, fire up regedit and add (or change) these keys in HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsNT\CurrentVersion\Winlogon:
(key -> value)
DefaultUsername -> your username
DefaultPassword -> your password
AutoAdminLogon -> 1
Note that all of these keys should be Strings (if you need to create them). Also keep in mind that this puts your password, in plaintext, in your registry. Consider yourself warned, but I have never had an issue using autologon.