There is a way to hide your user account from the Welcome screen. It is nothing but a small registry hack...

Open Regedit and go to the following location

HKEY\LOCAL_MACHINE\SOFTWARE\MICROSOFT\WINDOWSNT\CurrentVersion\Winlogon\SpecialAccounts\UserList

Create a DWORD and give it the name of the account you want to be hidden.

If you give the DWORD a value of 0, then its hidden; if you give it a value of 1, its visible.