High CPU Usage

[kumngetme]

I am trying to play Arma 3 but the game is lagging and freezing. I open Task Manager and it says I have 100% CPU Usage. I know that my computer exceeds the minimum requirements for the game but I couldn't find out why it was slow. At first I thought it was a virus so I factory reset my Hard drive and I wasn't convinced so I even changed the Hard drive. It still was slow I then decided that it wasn't a software problem. I checked the temperatures for my CPU and it is below 30 degrees. I think it is a hardware problem. I already looked on other forums about deleting stuff in Task Manager but it didn't work. Could it be my CPU? Do you think it is broken?

PC Specs:
Windows 10
i5 6600k
32 gb ram
H100i V2
MSI GTX 1070
1000w Power Supply
Asus ix Code

 

[CountMike]

It's not enough to look at CPU usage at that time but also it's frequency and number of threads used.

 

[Saturnity]

Factory Reset a HD? You mean reformat? Run a scan with malwarebytes.