i guess then you mean the screen where different users log-on?
here are some instructions on how to get rid of it:
stolen from http://www.msfn.org/win2k3/newuser.htmGo to Start -> Run -> and type in rundll32 netplwiz.dll,UsersRunDll and press enter. The User Accounts window will appear.
Make sure your name is highlighted in the User Accounts window and then uncheck the box Users must enter a user name and password to use this computer and then click on Apply. If you did it right, you will get another window asking for the password to use for autologon on your account name. Fill in both password fields, and you're ready to go!
i don't know how to modify this screen.