There is a possibility login automatically whit no need to enter user and password.
These methods work on windows xp, windows servers 2003 and 2008 as far as we know.
Method 1:

1. Start < Run
2. On the command line type the following string ‘ control userpasswords2 ‘
3. When user accounts window open just unmark the ‘users must enter a user name and password for this computer’

Method 2 for windows Xp here:

Install the windows xp powertoys from here
One of the configuration after the installation will give you the option to insert user and password one time and perform auto login.