I want to record games what should I use??
My PC is running on windows 8
If yo have a Nvidia card you can use Shadow Play.
There are two methods:
1) Hardware (NVidia Shadowplay) as mentioned, with almost NO performance hit. Requires 600 or 700 series cards. I'll repeat the link.
2) Software. Large performance hit, varies on quality, frame rate (i.e. 720p/1080p, 30Hz/60Hz etc)
Paid or Free:
Free: have to Google that, not sure.
I've only used Shadowplay on my GTX680 which works great. It's still in Beta and there's a small amount of stutter which will likely be solved. I was recording at 1920x1080 at 60FPS and my frame rate never went down in the slightest. I had VSYNC OFF to test the performance hit, but in reality I'd record with VSYNC ON.
Other people likely have much better advice than this. Shadowplay is really awesome if you have a supported NVidia card.