I stumbled onto a Disc cleaner Darick`s boot & nuke. Dban.
Back then you would burn to iso disc to use.
Many viruses can pop up later on if you just recover the disc even a total re-instal.
The were many options available to clean the disc like Canadian Mounty Police,NY Police Dept,CIA, American Defense Force & others they use to delete data.
I preferred the option that Zeros the hard drive disc 0-0-0 instead of 0-1-0.
It is or was a great tool for totally reinstall.
Probably still is just not shore with PC`s now in Solid state.
Picked up a horrible virus called Web Cake 3.
Very difficult to remove that was & i panicked changing all my bank account numbers even my IP address.
but like everything now a days more & more complicated.
Also if i hear my PC running hard ( noisy ) i sometimes open Task Manager & see what is running High CPU just in case some thing is not right.
Identifying what programs are legit is something else.