To eneable auto login on Windows XP follow the following steps:
- Click Run from the Start Menu,
- Enter in the box: control userpasswords2
- Click Ok.
- Click the user you want to auto login
- Uncheck Users must enter a user name and password
- Click Ok.
- Enter password for that user and its set
For other methods
See: [http://www.annoyances.org/exec/show/article04-103