[begin rant]

Don't system builders know what the purpose of thermal grease is?

Every pre-built system I've repaired or upgraded for people have had extremely excessive amounts of the stuff gunging up the CPU and heatsink!

All that should be there is a very thin (1mm) thick layer of thermal grease between the CPU and heatsink to fill in any undulations in the surface of both the CPU and heatsink plate, making a smooth surface to maintain contact with the most surface area between the two for maximum heat dissipation. Any more grease than that at it has a reverse effect and makes the heat dissipation less efficient.

[/end rant]

Deep breath...

Some may remember I had trouble removing a Pentium 4 from a socket a while back, while repairing a system for someone. The heatsink would not come away from the CPU even though it was unlocked from the motherboard. A hair dryer on its hottest setting eventually freed them and the amount of thermal grease on the CPU was silly.

And today, while waiting for a motherboard to arrive, I decided to strip down the system ready for the board. One removing the heatsink I have discovered that there was so much thermal grease used that as it had got hot it has spread out from just being over the CPU and has also gone all over the surrounding circuit board and circuits. That's one downfall of the older Athlon chips as they didn't have a heat spreader over the CPU and the actual CPU is exposed making it harder to clean.