Problem with FPS in video games [HELP!]

[ahkluh]

I have a pretty good gaming rig, I was playing fine and all just a few days ago. For example, CS:GO ran at 300 fps (high settings) and R6S 200-250 (ultra settings). Yesterday, I went to go play my games as usual, but; I was barely getting 100 FPS on CS:GO and 150-ish on R6S. Me, not knowing much about desktops, currently have no idea what is wrong or what to do. I was wondering if anyone has experienced this type of problem before and is willing to help, it'll be greatly appreciated. I uninstalled GeForce Experience, thinking it was a problem. Other than that, I don't know what to do anymore so I've just kind of dealt with the low frames, but I'd prefer much higher frames. (If you need more information and/or are willing to help, contact me at ahkluhwasherev2@gmail.com or discord ahkluh_#8590 [Underscore included]). 

Also, I have a problem when I insert my discs, it says application not found. 

 

Specs:
EVGA GeForce GTX 1080ti

16 GB of Ram (2x8GB) 
1200 Watt power supply (EVGA)

B350M Gaming Pro
2 TB of Memory (2x1TB HDD)
Raid 1
Microsoft Windows 10 Home 64-bit