If you want to disable the Windows XP login prompt for password.
How To :-
Disabling startup login prompt for password
1.Click Start and Run
2.Type "Control Userpasswords2" and press enter
3.Uncheck the box for "Users must enter a user name and password to use this computer."
4.Click Apply and Ok.
Disabling prompt for password after Windows XP resumes from standby or hibernation
1.Click Start, Settings, and Control Panel
2.Double-click Power Options
3.Uncheck the "Prompt for password when computer resumes from standby" option.
4.Click Apply and then Ok.