PCstats has an interesting article up about the most common ways to kill a PC. According to PCstats, the top PC killers are power problems, bad hardware, user error, and cooling issues. The article relates some painful incidents and anecdotes some users may be all too familiar with, including system-frying lightning strikes, and an accursed USB key drive that inexplicably "melted" and caused the untimely death of the machine to which it was connected.

USB mishaps and short circuits seem relatively rare next to some of the other entries in this list, but we did receive quite a few letters about them. The defining factor with these incidents seems to be the sheer randomness. A device might work perfectly for months or even years with a given system, then kill it the next time it is plugged in.

The problem with USB is that it transfers more power than most other I/O interfaces, so a short circuit can have disastrous consequences for the rest of your computer if the motherboard is not properly outfitted with board level fuses. Another possible cause is that the 'hot pluggable' nature of USB interfaces means that they are plugged in and unplugged much more than other I/O devices, leading to increased wear and tear and more chance of an electrical mishap.

How Not to Kill Your Computer This Way
Actually, there's no easy way to avoid this besides not using USB devices, which is not something we'd recommend. Taking a little time and care when plugging and unplugging your devices is probably the best path to safety. As an aside, several of our readers mentioned having problems specifically with devices that provided front-mounted USB ports, so you might want to reconsider using one of these if your computer case does not normally have front mounted ports. My recommendation is to put a USB hub on the desk, or use a USB port extension cable when plugging in devices frequently.

Note: That's a pretty old article (dated Feb.03.05), but still a good enough read for a lazy Sunday afternoon :)