A cleaner PC: dirt and dust can damage your rig and hurt its performance. Fight back!

It's still a few months until you begin spring-cleaning, but if your PC's insides are dirty, that could make for a sluggish system. Here's how to whip things into shape.

The Hassle: My PC overheats (the motherboard monitor beeps) toward the end of the evening, even though my home-office temperature is cool.

The Fix(es): I'll lay odds that your computer's case is full of dirt, dust and other crud. If you have a pet, the system is likely to be loaded with hair, too. Another bet: your PC sits on the floor, under your desk, gathering dust. Here's what to do.

Before opening the case, unplug everything--power cord, phone line, cable modem and Ethernet cables. After opening the case, touch the power supply to discharge any static and to ensure that you and the inside of your PC are at the same voltage. (Repeat this process every time you touch the PC's innards.)

Start by removing the foam filters, if your PC has any, on the fan vents. Gently clean the filters in a mild solution of dish soap and cool water, and let them dry before putting them back into place. (Better still: buy a foam air-conditioner filter, cut it to size, and replace all of the filters.)

Remove large clots of dust by vacuuming the fan vents from the outside of the case. However, be very cautious about vacuuming inside the case. Don't touch the motherboard or any add-in cards. At most, just suck away the dust that is lying on the base of your tower and on the bottoms of the system's empty drive bays. ...