How To Hide Administrator Account In Windows XP

 
First Goto Start -> Run -> Type regedit -> Enter
    In the Left Menu goto,
HKEY_LOCAL_MACHINE\Software\Microsoft\WindowsNT\CurrentVersion\Winlogon\SpecialAccounts\UserList
  
    In the Right pane, Right click -> New -> String Value
    Right click on the new String Value and click Rename
    Type the Name of the Account you want to hide.
    Hit Enter then Right click on the String Value again and Change value to 0 which hides it. If you want it to be Visible to all Enter the Value 1.
    Now Save and Exit the Registry and Logoff.
    Goto welcome screen and Hit ctrl+alt+del twice to bring up Logon prompt
    Type hidden Accounts name and password