Hide User Account with Tweak UI

You can also use the Microsoft Tweak UI PowerToy to do the same thing. 

Just click on the Logon key in the left hand side, and then uncheck the box for “Show <username> on Welcome screen”

Login to Hidden Account

You can still login to the account even though it’s not shown… You’ll just have to use a little trick.

At the login screen, just hit the Ctrl+Alt+Delete combination twice in a row, and you’ll be presented with the old-school login screen, where you have to manually enter the username.

Type the name and password of the other user, and login.http://www.microsoft.com/windowsxp/downloads/powertoys/xppowertoys.mspx