My friends PC has issues

[Tamxle]

My friend used to be able to play games just fine with his 144hz monitor. He has an i5-3570k paired with a gtx970.
his cpu temps are in the 40ish while idle and like 50's while playing games like rainbow 6ix siege and forza horizon 4. In Rainbow six siege he's getting like 30-40fps while playing.
He gets like 90-100 normally in rainbow six siege and it will now stutter and drop to 30fps. Anyone know why his cpu is acting this way? It also is at like 20% usage at idle

[Kappa-mikE]

You probably wont be able to get a good answer without posting some of the dump logs. Not savvy enough myself to read through them and give a straight answer, but it was the first thing i was asked for when i had trouble with my memory. Turned out i had a buggy chip and i needed to replace it. But it could be a whole host of things. Memory leak in a RAM chip like i had, or an issue with the onboard Gram in the 970. those cards are starting to age a bit (i have a 980Ti). hopefully this reply will get the attention of someone who knows more than I do, and knows what to ask for. Feel free to call me an idiot if i turn out to be full of shit. Not much more than a plug and play armchair expert.

[dgsddfgdfhgs]

may be malware.

laziest way to check is to partition some space / spare drives for new windows and clean drivers

[unsungheroist]

I would be happy to remote in with teamviewer. Pm me if you want live support. 

[martward]

What's the GPU usage and temperature like when it's stuttering? Also you can easily check which process is taking up which resources by going into the task manager. If you sort it on CPU it will tell you which programs are using the most CPU.