Power Down after shutdown in NT

Hi! Techpalls
Will anybody can tell me the procedure to powerdown the machine after shutdown in Win NT, as it is done in Win 98. I tried the registery keys under HKEY_LOCAL_MACHINES > SOFTWARE > MICROSOFT > WINDOWSNT > … AND changed the value for the option “PowerDownaftershutdown from ‘0’ to ‘1’ but it did not work. I also tried changing the value for the option “ShutdownwithoutLogon” form ‘0’ to ‘1’ but it also did not work. Please help.