Clean up your grungy PC

While you've got the case open, you'll undoubtedly notice dust in other places--quite possibly a lot of it. We've seen computer interiors absolutely caked from top to bottom.

If yours is, you might be tempted to stick a vacuum-cleaner hose inside and suck out the dust. Don't. Vacuums create static electricity, which is deadly to sensitive electronic components.

On that same note, don't be tempted to reverse the flow of your vacuum and blow the dust out of the computer. The dust inside a household vacuum can be harmful to your health, and you'll be spreading it all over your PC. Also, you risk blowing out sizable particles, which could physically damage internal components, especially if you're using a workshop vacuum. The beauty of compressed air is that it's clean and particle-free.

Before you start blasting, unplug your computer and take it outside--or at least to your garage. Now, working from the top down, blow out all that dust. (Put on a dust mask, unless you want a face full of grime.) As with the fans, be sure to spray air in short bursts, keeping the can upright and the tube at least a couple of inches from the hardware.

Check all the cables and plugs inside your PC. Make sure they're fastened securely and that you haven't knocked anything loose during cleaning.