It is very complex, will quite likely invalidate your Windows license, and you will take a large cut in performance.
Intel processors need Intel motherboards, AMD processors need AMD motherboards. The windows key is set to your motherboard(you might be able to get a new 1 of the same model if your original died for example). You can remove all the old drivers fine with a program called: "Remove Non Present Drivers". Which is in Hiren's BootCD. Try booting into safe mode the first time you do a major hardware swap like that and run Remove Non Present Drivers; then checkdisk just to be safe.