Just the beginning of the Demo, recorded at 1920x1080, maxed out settings (you can see them in the beginning).

Call of Duty: Modern Warfare Demo running on Vista @ 1920x1080 4xAA, max settings.

Just a test of FRAPS and it worked well enough, it dipped below double digits for a few seconds, but most of the time it runs at playable enough FPS. An odd glitch occurred with FRAPS though. During the loading phase, with the overview (which I didn't record, of course), FRAPS had the FPS listed around 500 to 600, which is impossible.

I may be able to get a smooth FRAPS experience if I ran it at 1280x720 (720p)

Specs:

Windows Vista Home Premium 64bit
CPU: Core 2 Duo E5200 2.5GHz (no OC)
GPU: Powercolor Radeon 4870 (No additional OC)
4GB RAM in Dual Channel (2x2GB)
Monitor: BenQ 21.5" 1920x1080 16:9 HD resolution