I was wondering which one was better for gaming if you kindly will please post in the comments your opinions.
Windows 8.1, it uses less memory(71gb) where as windows 7 takes up 100gb. That will probably improve FPS by about 20.
"Performance-wise, we haven’t seen any difference between Windows 7 and 8 when it comes to frame rates, so a given game will run at the same speed on the same hardware regardless of whether you have Windows 7 or Windows 8 installed." Source: PCAdvisor
Windows 7 is more stable and reliable. Windows 8 is trashy. Windows 8.1 is a massive improvement from 8. Still not on 7's level.
Windows 8 was designed for touch-screens. It is better for touch-screens, but windows 7 is better for non-touchscreens.