If you want to boot into Windows XP with no logon at all, try this:

1. Click Start and click the Run command.
2. Type control userpasswords2 in the Open text box.
3. Click OK.
4. In the User Accounts dialog box, click the Users tab.
5. On the Users tab, remove the checkmark from the Users must enter a user name and password to use this computer checkbox.
6. Click Apply. An Automatically Log On dialog box now appears.
7. Here you type in the user name and password for the user account that you want to automatically log on. For user name do not use Administrator. If you are unsure what user name to use then you should not be using this TIP.
8. Type in the User name, the Password and Confirm password.
9. Click OK.
10. Click OK in the User Accounts dialog box. Restart the computer.

Be aware that not requiring a logon is a big security risk. For that reason, you won't see this option if your computer is a member of a Windows domain. But if you don't have anything important or secret on your computer, and your computer is a standalone or belongs to a workgroup, take the risk!