Got some strange issues on my computer

So i upgraded my mobo and CPU to a MSI Z370 Gaming Carbon with an i5-6800k recently. Reinstalled windows and everything was fine for a week, worked perfectly. But today some strange issues have popped up.

One of the symptoms is that the System process is using a lot of CPU, it jumps up and down from about 8% usage to 25% usage. And my problems seems to be worse the higher the usage is. When the CPU usage is at 0.3% or whatever i have no problems with my PC.

One of the problems im experiencing is chrome is bare functional at times. Webpages just takes forever to load, but if im watching a stream there is no lag or anything on it, i just cant load any new pages. IE works perfectly fine, no issues at all.

The other main problem is that explorer seems to freeze from time to time, when i try to navigate my files or search for something it doesnt react for a few seconds and then starts working again. Other programs have no problems, unless the entire computer just freezes, which also have happened a few times.