"...a CPU really stinks when it burns..." Modern processors produce a lot of heat for their small surface areas. That's why they come with the huge aluminum and copper finned monstrosities of heatsinks that they do; they're not for decoration. Cooling is absolutely essential to the life of your CPU the split second after it is turned on, and to your system in general. Nothing will kill processors faster than a heatsink mishap. Some recent processors can survive without adequate cooling by throttling themselves down automatically, but this is a hit-or-miss procedure. In the most extreme cases like AMD Athlon and Athlon XP+ chips, the processor can cook itself to death in less than two seconds without a heatsink.

"...I fried a processor - a AMD Duron 950. I was testing out a motherboard, and tried to do things a little quickly. I knew that Athlon processor run hot and can burn out quickly, but thought I would have a little leeway with a Duron. So instead of clipping the heatsink in place while I started up the motherboard, I just held it down in place. It only took about 5 seconds (or so it seemed) before I realized that the motherboard wasn't going to boot, and I noticed a funny new smell..."

"Sure" you say, "I believe that, but I'd never be fool hearty enough to turn my system on without a heatsink." Ok, so what if your heatsink fan decides to malfunction? Or what if you didn't put the heatsink on exactly straight in the first place?

Or what if you used a little too much force putting it on and cracked the core of that new $700 chip? Or what if you forgot to remove the plastic covering over the thermal compound? Or what if you did everything right, then forgot to plug in the fan? There's a lot of ways that you can destroy your system if you are careless with the heatsink, which explains why of all our reader responses, the-dead-CPU-by-user category ranked number two.

"...a friend of mine bought a new 1.3GHz Pentium 3 processor and installed it into his PC. He then plugged everything in and turned the power on. After realizing he could smell something burning, he noticed he was still holding the processor's heatsink and fan in his hand!"

How Not to Kill Your Processor This Way

First of all, be careful. Follow the directions included with your heatsink when installing it; apply thermal compound or remove the protective plastic over the pre-applied thermal compound as necessary. Make sure it is installed in the right way on the CPU socket, and flatly sitting on the core of the CPU. Remember to plug in the power cord for the fan, and ensure you attach it correctly to a motherboard fan header.

Once you have the heatsink installed properly and working, keep an eye (and an ear) on it from time to time. If your system is making more noise than usual, or making grinding sounds, it could be that your CPU fan is on its last legs. You can try to service it yourself (as detailed in this PCstats Guide ) or get a new one. Finally, try to keep your system off the floor and away from excessive dust and pet hair.