Programm vorgaukeln, dass Windows heruntergefahren wird...

[Remko]

I know, this is true for several other less known api's. It means: "we were forced to document these api's due to the trust settlements. We hate that and therefore we (MS) encourage others not to use them, although we use them ourselves...". I think that since this function is present from win2000 upwards and still is in Vista it's allright to use it. But if you don't feel comfortable...
You could try WtsTerminateProcess instead.