Pc is not working how it used to

[User__]

(when i talk about frames im talking arma 3)
I had many problems lately. headset is broken and my pc has been being garbage again. I can go in to 1600x900 res on all low settings with no vsync and I'll get 15 frames and stuttering drops. I used to get like 80 Frames constant. People with worse Pc's than me get way better frames. Specs are 8 GB Ram, Intel i5 4690K Cpu and NVIDIA 760 2GB VRAM GPU. 1.8 TB HDD.(Windows 10) Can't afford new stuff. I am resetting my pc and reinstalling Windows as I type this. My disk usage does jump up to 100 a lot and that might be it but I litterally tried everything to fix it. every tutorial. I tested it several times and it said it wasn't damaged or anything. I defragged it. nothing seems to work. I'll update this if the reset of my pc helped. Majestic come to the rescue. my cpu is also running oddly low speed again while running arma and playing it too. drops down to 0.8 sometimes and temperature shouldn't be the issue because I checked the temperature and it shouldn't be high enough to lower speeds or high enough to damage cpu. and don't comment get a ssd cause I cannot afford it and I won't be getting it anytime soon. help if you can <3
my disk usage spikes alot up to 100%. I did finish the reset and it didnt help.



my specs

1.8 TB HDD
NVIDIA GTX 760
Intel i5 4690k CPU

HELP

 

[maxwellmelon]

" drops down to 0.8 sometimes and temperature shouldn't be the issue because I checked the temperature and it shouldn't be high enough to lower speeds or high enough to damage cpu."---sounds like your cpu temp is higher then it should be and your not wanting to address the issue or share with us that they are higher then should be

cpu throttleing can be from high cpu temps or bad voltage (regulators on motherboard/ or PSU voltage)