how to cool cpus

i have a cpu in a board that its always been in. as of late its been overheating. you could argue that it was the cpu fan that i bought since this started happening but i dont see why. i have a p4 775 socket, and a manhattan brand fan on top of it. i tried applying new thermal paste. I tried reseating the fan and cpu, i even put another fan right on top of it. What can i do to keep it cool?

Well which was is the fan blowing the air? Into the heatsink or pulling air through the heatsink?

which fan? the cpu fan is blowing which ever way it does, can't put it on the heat sink any other way, the other one i put on top of that fan is blowing down into the heat sink

Two fans on top of each other doesn't increase CFM, or flow. Quite the opposite actually.

The fan on the headsink should be SUCKING in air on top, and blowing it through the heatsink to disperse the heat.

Make sure the heatsink is making full contact w/ the CPU... (if the heatsink is warm/hot, you're good to go).

What is the temp reading you're getting?

yeah, it was just an idea. the heatsink gets plenty hot. the coolest its read is 58 C. when it shuts down cause of overheat, i check again and its like 76 C