How Many Files Do You Understand

I just did a virus scan on my PC. Its just a lowly laptop. On just the internal 100GB drive. Now let me be clear. This is not just Joe Consumer's PC. I use this for software development, music recording, storing pictures, etc. So there are lots of programs. A lot of crap. I suppose its a power users PC. But so far it has scanned 4,724,604 files. I have no idea what most of them are. I can't believe there are even that many files on this machine. I would guess a huge number are not even used. This is a MacBook Pro running both OSX and XP in partitions. This does not even include my extenal drives with pictures and music files. WTF???? How is this possible. I am clueless. I suppose I should continue backing it up.