My pc is showing 100% disk usage on 1MB/s when the gpu is under load.

I started experiencing this after my brother installed some malware on my pc while playing CS GO. I have removed all the malware i could find and have ran memory and disk tests which have shown me nothing but positive results, but when i run furmark the disk usage climbs to 100%. I also have noticed my nothbridge overheating which might be the issue. I also have a shady 600W psu that needs changing because it is old and I don't trust it.
I have
CPU: intel i5 3330
GPU: Nvidia gforce gtx680 refrence
RAM: 8GB kingston value ram
PSU: 600W super cheap generic psu that came with the case
HDD: wdc wd5000aakx-001ca0 500GB that needs changing
MOBO: msi MSI H61MA-E35 (B3)



https://gyazo.com/411d0b6f4ff516a4728e7ab9494c0832

https://gyazo.com/e2e8feba8cf20acd54e572271b1dc81f

https://gyazo.com/891a44c7f8227e9753e1c955ef465168

Edit:

I found out the reason for my hdd stopping while under load was that one of my 6 pins was a 2molex to 6pin adapter and one of the molex cables was also the one powering my hdd through a sata power cable.So i plugged in a different one and now it's fine. Ty for all your help.

Furmark is an intensive program designed to do that

Sounds like some malware may still be in there. Check the user app data roaming file for something strange

Edit:
Could be an hardrive issue too. Run some HD diagnostics

HDD TEST

Run SeaTools to check the integrity of your HDD. SeaTools Tutorial