When putting my new rig together last night I had a problem with the stock Heatsink on my Q9450 not fitting on my board (P5K-E WIFI-AP). the legs weren't long enough to clear the transistors around the CPU and still snap fully into place without the fins resting and putting pressure on the transistors.
So, I pulled it off and used a q-tip to clean the thermal grease that had been pre-applied to the stock HS and wanted to make sure it would be OK. There is a bit of a stain where I cleaned off the TG from the CPU but I can read the text on the CPU so I belive its pretty clean. Going to get another HS today and finish my build but wanted to know if I needed to use any special cleaning product on the CPU before appling more TG and a new HS.
I use 91-95% isopropyl alcohol and it cleans things fine. There are a couple commercial cleaners out there, but I think they're a waste of good money. Yeah, avoid the lower quality alcohols as they contain a lot of impurities, oils, and junk that are not good for computer chips.
You can get 100% at a drugstore. 70% is OK. Avoid something called "rubbing alcohol". It's usually 70% isopropyl, but it has lanolin in it - leaves a film. A piece of a clean coffee filter works well for cleaning - doesn't leave lint behind.
works great for me and i wouldn't use a q-tip either. small cotton strands could come loose from it...i personally use a lint free cloth, such as those in eye glasses cleaning or you could pick some up from your local electronic store.
luckily since I was just putting the machine together the thermal grease had never been heated up and it came right off with the q-tip...i picked up an Arctic pro 7 today and a little tube of xigmatex grease sicne they were out of artic silver. Hopefully the system will post and boot smoothly tonight after I put in the new HS and finish connecting everything.