I've had a machine come back to me multiple times now with the MBR/boot sector trashed. It crashes while trying to load the MBR/boot sector without a warning. Basically just gives a black screen rather than complaining about media or anything else. This last time, the customer only had the machine for about 2 weeks before it happened again. All the AV and anti-spyware was up to date, but I suspect he must be getting into something bad.
It doesn't appear to be hardware related. The first time it happened I went ahead and replaced both the hard drive and controller (as an upgrade in speed, size, and noise level!) since he didn't have anything critical on the old drive. I can run the computer for days here and nothing bad ever happens.
So, is there a common virus/trojan floating around out there that's doing this right now? If so, is there a published repair procedure?