Random FPS drops in all games?

Airitech

Honorable
Dec 13, 2013
15
0
10,510
Hello, i had no trouble with Windows 7 Pro 64 Bit, but when i lost the disk and the CD Key i was forced to re install my windows, and i had 8 Pro 64 Bit.
Recently been playing hardcore games like CoD Ghosts, Crysis 3, Bf4 and i get random fps drops from like 74 fps to 20 then back up to 74?
Dont even say the Drivers are out of date. I have the recent NVIDIA drivers.

Specs:
AMD FX-9370 8 Cores @ 4.4 GHz Cooled by a H100i never goes above 40C
GTX 760
8gb Ram DDR3

What seems to be the problem? Windows 8?