20,000 Files scanned? Dafuq?

Again, my computer is deciding to fuck up, and I can't do jack shit about it. When starting the client, it stays in 33% and says "calculating differences | 20,000 files scanned". Of course, that was yesterday, and it got me annoyed. It just went on and on and on. It kept going. I need help. I can't continue. I'll keep it up, and leave posts as the more progressed it goes.