Just for the record, a set of symptoms on a new machine which stumped me over a period of months, none of them occurring regularly enough to prevent use of the computer : * bsods * slow booting * memory dumps - with mention of a different driver each time * refusal to boot, stopping at the bios screen or at a black one with a cursor, requiring a hard reset * the Windows flash screen showing extremely dimly while booting very slowly - you could easily miss the "Windows" text if not paying attention * going away for a period of a minute or 2, not long after booting to xp, - no activity, no response to mouse or cursor - then working fine the rest of the day * regular long wait while closing down at "Closing Windows" stage I did all the usual tests - as outlined by Julio. The culprit ? A hard disk, actually an Intel ssd. I replaced that and the troubles stopped. Until, ironically, I sat down to write this - when another bsod occurred. Just hope that's an isolated case.