I have a couple of Win2k machines that are still coming up with a "System is shutting down...intiated by NT Authority/System." One of these machines was patched for the RPC vulnerability but later still began shutting down several times a day. Checked the IRPStackSize setting in regedit and apparently Norton Anti Virus had overwritten the correct registry value with a line of garbage. Fixed that and the machine ran fine for several weeks. But now is back to shutting itself down. Checked the IRPStackSize setting this time, and it was fine...set for 11. Any more ideas? The other machine I finally had to reghost, but it will be a pain to do that to this one. HELP!