Recently my gf bought a new desktop with Windows 10. For some reason her CPU and/or disk usage stays above 90% constantly. I've heard this is a common issue with the Windows 10 OS but is there any way to fix it?
Probably windows is just downloading all those gigabytes of updates.
You can use Resource monitor Cpu and Disk sections to get more info about processes that are causing the activity.
No, it is not that paranoia spying thing. Do you think MS really wants to look at your pitiful self porn crap? Like they don't have anything else to do. You and three billion other users.Go into task manager and see where the resources are being used and stop any processes that are hogging your resources and stop them. Also stop any unnecessary programs from running at start up.
W.P.
I would try running malwarebytes and maybe superantispyware, (both free), and see if it is an infection issue.
If those things don't work maybe reload the OS. No, not fun.
What is important is to make the machine run right.
W.P.
Errrr. A/V and antimalware options are completely different, so no. Malwarebytes catches many, many things that an A/V won't. What do you have to lose at this point? Do something.
W.P.