Hide user from login screen without deactivating it

You need to remove the "interactive logon" right from the users. You can do this from the "Users and groups" node you get from right clicking on "Computer" in the start menu and choosing "Manage".

Unfortunately that too is not included on win7 Home premium or below - to achive the same thing on those editions you need to

1) Download the Windows 2003 resource tools 2) Use the "NTRights" command in that toolkit to (somewhat counter-intuitively) grant the "SeDenyInteractiveLogonRight":

ntrights.exe -u <username> +r SeDenyInteractiveLogonRight

That will stop the users from showing up on your login screen

1. Run the Registry Editor (RegEdit.exe).

2. Navigate to the following registry key:

   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\
    CurrentVersion\Winlogon\SpecialAccounts\UserList
   

3. Select UserList.

4. In the right pane, right click on any blank space, and point to New -> DWORD (32-bit) Value.

5. Name the new DWORD registry value name as the exact same name that match the name of the user account to be hidden. Double click on DWORD registry value, and set the value data to 0 in order to hide the account from Welcome Screen.

6. Exit the registry editor and logoff or restart your computer to see it in effect.

— Source: MyDigitalLife Article