Clean up your grungy PC

Perhaps the most serious dirt-related threat to your PC is dust in the fans. Dust constantly gets sucked inside the case. Over time, it clogs both power-supply and cooling fans.

As more and more dust accumulates on the blades and in the motors, the fans have to work harder. If the buildup goes unchecked, the fans may significantly slow down or fail completely. This can lead to serious overheating inside the case, which can cause component failure and, ultimately, data loss.

Once again, you'll need your trusty can of compressed air. Start by powering down your PC, removing the case lid, and locating the various fans. Starting with the power supply, blow through the internal slits from inside the chassis, aiming so dust will exit the back.

Next, blow into the intake fan (if there is one) to push more dust out the back. Finally, blow the blades of the rear exhaust fan clean. If possible, aim just beneath the center, where the motor meets the fan assembly, and blast again. Repeat the process for each fan, keeping the can upright at all times.

Now restart your PC, and while the fans are spinning, spray them once more--very briefly--to really send the dust flying.

Don't forget to run air over the vents on your case lid, too. If they're encrusted with dust, the fans won't be as effective expelling warm air.