Need Help, PC FPS issue

[THExHARBINGER]

hey guys, so I've been having some problems the past couple of days.  My PC has decided to practically stop running games.  I have a MSI 980 and an Intel 4790k.  The GPU is fine since I tested it with a stress test.  I use a benQ 2430t 144hz monitor, and ill use CS:GO as my example. Usually when I play counter strike I run it perfect on ultra 144 fps not a problem. Now when I run it I get unsteady 20-50 fps.  Same goes for any other game that I could play on high fps before, now they all barely get over 15-20 fps.  Then today after a weird huge windows 10 update this happened while it was plugged up with my DVI.  

 

if anybody knows what's wrong with my PC please let me know would be much appreciated.

[Paling_HW]

do a cold start not a reboot, i had the same issue after win10 update, restart didn't fix it for me but turning it of for 5min and then turning it on did strangely

[THExHARBINGER]

do a cold start not a reboot, i had the same issue after win10 update, restart didn't fix it for me but turning it of for 5min and then turning it on did strangely

I have already tried to leave it off and turn it back on after about an hour and still nothing.