Auto logon can easily be setup on any Windows NT machine by adding two strings to the registry and modifying two others.
Start regedit and navigate to the following key:
Double click on DefaultUserName and enter the user name you wish to use.
Add a new String Value and name it AutoAdminLogon Set it's value to 1
Add another String Value and name it DefaultPassword Set it's value to the password of the user in "DefaultUserName"
NOTE: if the password for the account is blank, the AutoLogon will only work one time, then revert back to a manual logon.
Depending on your settings, modify DefaultDomainName to the name of your domain or the name of your computer.
To logon as a different user, just hold down the shift key while logging out. The normal logon prompt should appear.
To disable AutoLogon, change the value in the AutoAdminLogon to 0