I just wanna say.. If you have a computer that's overheating and a fan isn't fixing it something is probably wrong
(dust, goop: too much/too little, smashed case, some sort of clogage)
HOWEVER if your looking for a super cheap method to keep your system cool i recommend buying one of those blue lighted dual fans that go in usb on ebay.. they are literally 7 bucks with free shipping and keep it at a decent level (ASSUMING IT ISNT ON FIRE).... worked for me for 6 years now... even with overheatig laptops (after a fresh thermal paste/ dedusting session)
im talkin a NOTICABLE difference.. watch w/ speedfan
plus it has a light its sick in the dark.. i even have 1 under my ps3 hahaha. usb power!