"You can get Windows XP to automatically log on a user account during the startup process provided that the following conditions apply:
1.The Welcome screen must be available
2.Guest account access must be turned off
3.There must be only one user account on the computer
4.and that user account must not have a password.
If all of these conditions are met then Windows XP will not ask you to logon, it will take you straight into your user account."