Home computer use: 5 million files?

Self-tutoring about home computer use: the tutor mentions something he learned from a virus scan.

Every so often, I do a full system scan of a PC. Today I did so, on a computer I use a lot. The scan took longer than I’d expected.

The scan reported no threats found, and that it had scanned over 5 200 000 files.

I re-installed Windows on another computer a few months back; it sure worked a lot better afterwards. Moreover, the occupied GB on the hard drive went down from about 110 to about 45. Full system scans, needless to say, became much quicker.

This computer is newer and faster than that one, so isn’t being dragged down, performance-wise – yet. However, it apparently could use a Windows re-install as well.