A recent Microsoft update changed the way I logged into my workstation. Microsoft Windows XP use to boot directly to the desktop, now boots to a logon screen. To get past this behavioral change, I found the following information to work as advertised.
- Click Start > Run and type control userpasswords2

- Clear the check box captioned Users must enter a user name and password to use this computer.

- Click OK
- Enter the user name and password for the account you want to log in to at startup.

Source: Google