I was cleaning out my computer today of dust and removed my fan from my CPU in order to clean it well. Since I have put it back on, I keep getting the overheating signal from my CPU when it is under a load. My BIOS has the warning sound set at 80C right now. When I go into the BIOS, I can watch the temp rise and fall depending on the load.

What I need to know is, what the little glob of sticky grey stuff does that sits between my CPU and my fan? I figure that I need more of it now that I took the two apart but don't know what it is called or how much of it to use. The amount used when I first built the computer was just what was provided with the CPU and those directions were followed.

I have read a few posts here that indicate that I should buy something that I then spread over the entire CPU and I wanted to know if that is accurate. What does that goop really do?

Thanks so much for your quick reply.

That gloop as you call it is known as thermal compound, and if you have completely removed your heatsink from the cpu then you should really clean off the old compound and add new. To clean it of the heatsink and/or cpu you should use a NON-acetone based cleaning solution and a cotton wool bud.when it comes to adding new compound then you should place a small ammount in the centre of the cpu (how much depends on what cpu your using) but this ammount should when compressed between cpu and heatsink be enough to cover the chip only and not the pcb that its on. When replacing the heatsink make sure that it is on correctly as an improper contact will cause a overheating problem. this is what the thermal compound is for to make sure that you have a full contact between cpu and heatsink therefore making heat dissipation through the heatsink possible, ie:- better compound=better contact=better heat dissipation=better cooling=more efficient cpu

I THINK

So I can buy this thermal compound at Best Buy, you think? That is the only place around here (within 45 minutes of me) that would possibly carry enough computer stuff to have it.

I am using a AMD Athlon 2500+ with no overclocking. I am not a gamer either so it really is not put under much stress except when I have lots of windows open or am doing movie editing.

When I took the fan off, it just had a small square of the stuff in the middle of the CPU where the two touch, so you are recommending that I put more in just the same manner after cleaning off the old, rather than spreading it all over the CPU like some posts had suggested?

Thanks again for any help.

best buy really isn't a DIY computer store, they generally only sell add-ons to boxed PCs, they may have some, but I don't believe they sell CPUs (or thermal compound to install it with). you can order it from newegg.com. arctic silver 5 is commonly known as the best thermal compound you can buy, check it out here

the stock heatsinks for Athlon XPs had a thin layer of thermal grease preinstalled (you simply peeled off the wax paper and slapped it on). while the stock grease was good enough, it is only useable once.

newer CPUs (like athlon64s) have a metal heatspreader over the CPU die, in those cases it is best to spread it around the entire heatsink (although it's not required). Since you have an Athlon XP, the die is exposed. you only want thermal grease/compound on the die itself, and not the rest of the chip.

First, clean off all traces of the old compound with alcohol, then put a tiny amount of grease on the die and spread it evenly, don't touch it with your bare skin use an unused credit card or your finger inside a plastic bag or something