:LOL: sorry Overread but that is definitely not the problem. If you get a bit flipped when your copying something on the computer you'll more than likely know about it. You'll end up with a msg from windows saying CRC error or something to that effect. In any case given how data is stored on the computer the files which are copied more often are actually less likely to have errors relating to magnetic failure, and even then that is more often than not a recoverable error due to ECC (Error Correcting Code) that is stored along with the data.
Vista was many nasty things to me, but it never bluscreened. That is the fault of dodgy drivers about 90% of the time, 9% is hardware failure which is why blue screens exist in the first place (abort before it breaks), and if you don't take into account users installing dodgy software or drivers, then user error makes up what's left.
The likely scenario is that in time JPEG compression algorithms in cameras have considerably improved. There is a LOT and I mean LOT to JPEG compression besides a quality slider that gets done in the background and is up to the coder to decide.
If you save at the best settings possible, JPEGs only start to visibly degrade if you open and resave them more than about 5 times. Until that point what you are losing with JPEG is data that you can't see. It definitely makes sense to store TIFFs or DNGs (don't like the idea of storing proprietary RAWs) if you're going to re-edit files at a later point, however if you don't, it doesn't.