My PSU is a hk380-12gp. I run a HDD, a Hitachi HCS5C3232SLA380 290gb. My CPU average temp is 46 c to 48c, and my GPU runs at 29 c to 30 c. My ram usage is around 70-71% and my HDD runs at 80-90% when I'm gaming.
I actually bought this pc off of someone last Christmas, windows runs fine until I start playing Fortnite. I play numerous other games but Fortnite it the only game I stutter in.
If it doesn't find anything, then I'll be convinced it actually is factory reset.
That drive usage is pretty high, considering your ram isn't maxing out yet; when the ram does max out, the system will then write temporary files to the drive.