Deleting fonts from NT

Hi,
has anyone ever tried to properly delete a font from NT using RemoveFontResource(), clearing the Registry, deleting the ttf-file and sending WM_FONTCHANGED-messages?? It just doesn't work! Strange things start happening like getting a RHSAC-Attribute for that font-file (which actually doesn't exist any more but is shown in explorer). I would apreciate if someone might have an idea how NT (and probably Win 9x) deletes a font and cleares its resource table!
Thanks in advance!