A solution (this enables auto-login):
Start -> Run... -> control userpasswords2
Uncheck the "Users must enter a username and password to use this computer" checkbox. Enter the username and password to be used for the login, and press OK, OK.
To disable the Welcome Screen:
Control Panel -> Users/Accounts/Whatever, uncheck the "Use the Welcome Screen" and the "Enable Fast User Switching" checkboxes (the latter of the two will save on system resources.
If you still want a login, but no Welcome Screen, just do the second instruction.
That will help.