In reality, if that first situation occurs, 99% of the time the person will delete the file, empty recycle bin, be paranoid about it for a while, then that is the end of it.

The truly paranoid but clueless may also destroy, sell, give or throw away the computer for good measure (seen this).

The paranoid and smart(ish) usually delete and do a system scan (Defrag, chkdsk), maybe format to start fresh as well. Some may take the opportunity to upgrade to an SSD or M.2 drive if don't already have it.... just for good measure.