Switching graphics cards

Hi there,
I've got a laptop running Windows 8.1, and looking at my Device Manager, I see two graphics cards listed—the integrated Intel HD and then the dedicated AMD HD 7670M. Does the system automatically kick in the AMD card when I launch a game, or do I need to manually toggle between them?
I've tried messing around with the settings myself, but nothing has worked so far. I figured I'd check here first before I start poking around too much and potentially breaking something.
Thanks,

So, have you actually tried running a game yet? Just curious if you'll get a smooth frame rate or if things start stuttering on you...

Larry Ortiz5 said:Have you actually tried launching a game yet? It's worth checking if you'll get smooth frame rates or if everything starts stuttering...

Well, Call of Duty 4 and 2 run just fine; I just haven't pushed them to high performance settings yet.