Some users have been experiencing the Vista “blacK Screen of Death” (as opposed to the pre-Vista “Blue Screen of Death” where

after a reboot the Windows Vista PC boots up to a black screen with a white mouse cursor and nothing else ever loads (no logon screen, etc).

Turns out the problem is due to the Remote Procedure Call service running under the LocalSystem account rather than the NT AUTHORITY\Network Service account. (If that’s confusing, just know that the steps below can fix the problem in just a few minutes, instead of having to totally reinstall Windows Vista).

Logic IT Consulting lays out the step-by-step instructions here. If you get a distress call from someone describing the KSOD, grab your Vista install disc and these instructions–it just may save hours of recovery work.