More misc stuff
Brandon Paddock: "In fact, Vista is probably the *only* OS that's "immune" if you use BitLocker." No, it is not. At best, BitLocker encrypts only the OS partition and would have no effect whatsoever on the infectability of the disk. At worst, BitLocker encrypts the whole disk and infecting it would have messed it up. But it wouldn't have *prevented* the infection in either case.
Pooper Scooper: Good point; maybe the disk was indeed infected before Vista was installed on it. Vista writes a partition table entry in the MBR - but it doesn't overwrite the whole MBR, so its installation wouldn't have removed the virus. This virus doesn't "change the location of the MBR". It saves a copy of the original MBR in another (unused) sector and overwrites the *program* part of the MBR with its code, leaving the data (i.e., the partition table) intact.
Steve Coffman: "Even if you had an infected boot sector, it would be highly unlikely they would be able to do much in Windows itself". True for this particular virus, false in general. If the virus is like Michelangelo - an MBR infector with a destructive payload that can trigger at boot time - it would have destroyed the contents of the infected disk (well, a large part of it, anyway) when it triggered - and trigger it would have, if the computer was booted on the trigger date.
malware: You are wrong - viruses *are* malware. The term "malware" means "malicious software" and includes all malicious programs of any kind - viruses, worms, Trojan horses, password stealers, addware, spyware, and so on.
Vladimir Plouzhnikov: A floppy disk drive is also used to transfer files from one computer to another - not just for booting the computer.
Geoff Mackenzie: "I wouldn't assume Linux boxes are susceptible". And you would be wrong. They *are* infectable by boot sector and master boot sector viruses. Of course, once the OS loads, the virus stops running.
"the machine would be rendered unbootable by the infection". No, it wouldn't be.
"I have my doubts it would have handled relocating the real boot record properly". It would have. Trust me, I know.
Anteaus: "This should hopefully ram home the fact that any OS which automatically runs (or offers to run) any software found on an inserted CD or memory-stick is simply begging for a Take Two of the old "Brain/Stoned" class of exploit." While having the OS run automatically stuff from mounted disks is indeed a bad idea (which, BTW, Macs do too), it has absolutely nothing to do with boot sector viruses like Brain or Stoned. As others have said multiple times, these viruses run and infect *before* the OS has had the chance to load, so blaming the OS for failing to prevent the infection is simply stupid and ignorant.