You may be tempted to place your PC wherever it's convenient, but remember that the placement affects its performance. If the desk is facing or adjacent to a wall, some users may be tempted to force the case against the wall to maximize desk space. The majority of PCs pull outside air from the front and bottom, and exhaust it at the rear. Blocking the rear, or any of the vents around the case where warm air can escape, can cause thermal issues. Many PC manufacturers recommend maintaining anywhere from 2 to 8 inches of clearance at the vents, depending on the machine.