Gotcha e-liam - M$ writes the fix, then comes Mr Cretin and writes the worm as he's clever enough to know that 99% of users still don't bother updating windoze - I take it that's what you meant.
Feline, I don't recall the exact sequence of events as I was sitting there sweating with the customer breathing down my neck "is everything allright every 5 mins", "fine don't worry, go make another cuppa tea.."... BUT, I do recall the PC slowing down to a point I thought he might have bought a Celeron processor but my suspicions were awoken when I saw it was a P4 3.0, and that it seemed to stall quite a lot. I managed to run the NAV update and ran a full system scan, and hey presto Sasser came out. The rest as they say is history.
By the way, when I said it ain't black magic, I was talking about my own skills, I'm no Harry Potter.
Charles
ps. you might get viruses slipping though if they creep into your system in between updates - in the last few days my NAV has updated 3-4 times, might want to check that yours is set to auto-update too.