If you have not done the inspection mentioned in the previous article - How to Clean your Case, now is the time to do so. Look at the blades of the fan in the back of the computer. Also look at any vents. Is there clusters of dust there? Is there grime caked on to it? If so, the inside needs to be cleaned. If the fan blades are clean but it has been several years since you have cleaned the motherboard or if the computer is around cigarette smoke, it probably should be cleaned anyway. Dust and particles in the air (like cigarette smoke) can build up on the circuitry of the motherboard and cause it to heat up and/or corrod...