Not too many things wrong, to be honest. Ocasionally, when I start it up, it changes the resolution to the lowest possible. Also, it seems to have some issues with Steam online games, I get a lagspike about once per two minutes that lasts for three or so seconds. I'm writing down that as a Steam problem, though.
But no, apart from the resolution changing, nothing wrong. Hell, even my old desktop didn't have too many problems after five years of heavy use. Eventually the graphics card overheated and died so I decided to get myself a new computer. That compared to my sisters identical desktop that died 2 weeks in. She got it fixed, and since then it takes 30 minutes to start it up. Good thing she doesn't use it much.