Just remember, if you use specialised back-up software, to make sure you know where a copy of that software is. All I shall say on the other stuff is that I've assembled my own computer, and so there's things I'd be willing to do which would worry other people. But if I had the cash, I'd look at using RAID, mirroring for reliability. That's a controller card, and an extra drive. Cleaning out the dust, and fitting a hard drive cooler, aren't dreadfully hard jobs. Turning the room heating down a few degrees can help too. Yes, it depends on climate, but the heat your computer pumps out can be all the heat you need. The cooler the air going in, the better.