Restrict the air flow and we make the heat build up. Air cooling systems rely on heat sinks to pull the heat away from components. Most heat sinks for Pentium and Pentium II processors include fans to provide additional cooling. The power supply is the next source of heat in the computer. It is the most often overlooked source for overheating problems.
Power supplies come in many different price ranges and designs.
I did a great deal of research on the motherboard, processor, video card, sound card and network adapter, but neglected the power supply. I was using the power supply that came with the case I had chosen purely for aesthetics. The design of the power supply had a fan on the bottom forcing air through the power supply directly toward my processor. I question this as hot air rises and you are heating the air through the power supply and then directing the hot air down. The hot air then rises and goes back through the power supply heating it even more.