In tip 0037, I described the PowerDownAfterShutdown setting, that only works if your HAL supports it.
Boot to an alternate install of Windows NT and copy \I386\HAL.DLL.SOFTEX from SP4 (or later) to your origonal %SystemRoot%\System32 folder as hal.dll. If you have a standard multi-processor, copy \I386\HALMPS.DLL.SOFTEX to your origonal %SystemRoot%\System32 folder, also as hal.dll.
You may also wish to implement a new default shutdown setting.
I have tried this on various standard HAL computers, including a multi-processor, and it works.