How do I record the games i'm playing on my computer?

FRAPS is good, but you'll have watermarks if you don't register it.

OBS is also good, has more features, and is completely free. It just requires a little extra effort to set up. Then it's almost stream-ready (if your processor can handle gaming and streaming at the same time).

Obelix

www.bandicam.com

Download OBS

dk