BO2 doesn't push anything
Metro Last Light DOES push it though. I think its one of the hardest games out to run on maximum settings. And also one of the best looking games currently out.
Does the sound work before you enter into the game?
Windows Sound Settings?
BO2 is fun for a run through in the sense of just gunning stuff down. MLL was a fun game
Meh, I've heard reports of MLL being used as a benchmarking tool for gaming PCs even. I tried the first scenes, and there was some noticeable lag on 1920x1080 default.
About the sound issue, the audio pretty much works (System Sounds, WMP, iTunes, etc etc), but I can't seem to find BO2 or MLL on the Volume Mixer when I run either. I think the PC needed a restart as the memory usage was at a constant 90% or higher.