You can hide user accounts from the Windows Welcome (log on) screen through the registry. This works with Vista and all later versions.

1. Start up regedit.
2. Navigate to the key: HKEY_LOCAL_MACHINE\Software\Microsoft\WindowsNT\CurrentVersion\Winlogon
3. Under Winlogon, create a new key called SpecialAccounts
4. Under SpecialAccounts, create another key called UserList.
5. Under UserList, create a DWORD value for each account:
   • Name: the full account name (including spaces)
   • Type: DWORD (32-bit)
   • Value:
     • 0: hides the account
     • 1: shows the account