Originally Posted by notabook

I've only had one computer ever do something similar, make sure that after you clean off the thermal grease/cooling solution just put a dab on the very center of the chip. Since you are new to putting them together let the heatsink pressure do all the work... don't you bother spreading it out. Make sure you clean off the thermal grease well before re-applying. Make sure to use a high-grade Isopropyl alcohol (preferably 99%) when cleaning. When applying the heatsink to the chip, make sure to gently bring it down vertically as possible (try not to bring down the heatsink at an angle).

After you have the heatsink seated properly, clamp it down using whichever tools they have available. After you have secured the heatsink to the mobo, twist it slightly to the left and the right (it shouldn't move much at all, just a little bit in either direction). This will help squeeze out any trapped air bubbles and make for a better seal. After this you really just need to burn the computer in... thermal grease isn't immediately effective, it takes a few days for it to start really cooling properly, especially arctic ceramique (it took about a week before my computer temps dropped a few degrees).