100% disk usage problem. I've tried everything.

Hey.
So as the title says im having disk usage problems for weeks now.
It goes from 0 to 100 in a second everytime i open a program, it can be anything from paint to world of warcraft.
Everything have become so much slower last month.

Anyways when i finally found out that my disk usage was extremly high all the time i started googling and i have done that for weeks on and off now. I have legit tried everything, tried every little thing i read.
And today i gave up so i reinstalled my windows hopping it would fix it but it didn't.
When i was installing programs on the new win8 it looked like this while i was installing alot
But a minute after that it looked like
It's been way better after my reinstall but it still not gone

I just restarted my pc and this is how it looks 30 seconds into startup

So im turning to here as my last hope, i just wanna know whats wrong and if i can fix it. any help is very appreciated.


Edit: I can't even remember all the things ive tried, but if you guys have any tip of what i can do i'll tell you if i have done it or not.
Windows 8.1 pro
Intel Core i5-3570K
8,00 GB RAM
64-bit

Hi vroksnak, haven`t read what you have tried, but it might be useful to see if it is hardware or software related. I suggest you make linux boot disk or a usb with linux installed. this should tell you if the problem is hardware related or not. If disk useage is still 100% when running linux then it looks like it could be the machine, if disk useage is ok then the problem is windows related. If you don`t know how to make a linux "live" cd or usb just google it. There are many step by step videos and pages that will show you how. I assume you have tried booting in safe mode?
Good Luck Hugh

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