Each type of cooing unit and processor will have its own way of being installed. If you didn't buy a boxed retail processor that comes with installation instructions, visit the processor manufacturer's website for installtion instructions. You can also find third-party instructions by entering a suitable search term in the Google search box provided at the top of this page (with its Web Radio button enabled).
Most recent desktop PC processor coolers can be fitted to motherboards with either a Socket AM2/AM2+ (for AMD's latest processors), or a Socket LGA775 (for Intel's latest processors). However, some current coolers are designed to fit only a specific socket type (AM2 or LGA775).
Earlier processor coolers can also be specially designed to fit an AMD- or an Intel-based processor socket. For example, an AMD Socket A or an Intel Socket 478, so if your PC has a processor the predates the current Socket AM2/AM2+ and Socket LGA775 and you need a new cooler for it, make sure that you get one that fits that type of motherboard socket.
Visit http://www.arctic-cooling.com/cpu.php for access to coolers for the different AMD/Intel motherboard socket types.
If you want to buy a fancy cooler, you should check that it will fit in your PC's case. Most coolers should fit in a standard ATX tower case, but some of the larger coolers might be too tall.
AMD uses a fold-over clip on the cooler that attaches it to the socket and Intel uses a pushpin design that plugs into the socket. Both are easy to install. However, Intel's Socket 478 processors can require a backplate to be fitted to the back of the motherboard. The cooler's heat plate is screwed into it. The fitting of a new cooler that requires a backplate can be tricky if the PC is already built, because you have to remove the motherboard. If you are building PC with a motherboard that uses a backplate for the cooler, fit it before you install the motherboard in the case.
Keeping Your CPU [Processor] Going If Your Cooler Fails -
"We took low-cost and high-end processors from both AMD and Intel and put them to the test with regular cooling, as well as in a simulation of a broken CPU fan. In so doing, we discovered that there still are considerable differences between AMD and Intel.