Can't run video capture

[Timothy]

I want to make a video of a portion of the Penumbra game (the Tech Demo) so that I can show my friend, who probably couldn't handle the download. I've seen a lot of videos of the game on YouTube, and I figured it would be simple. I've downloaded two programs to try: HyperCam, and CamStudio, a freeware program that appears to work just as well.

The problem is that I am perfectly capable of running Penumbra, and I have no trouble with the Camera programs, but I am unable to successfully run both. Gameplay gets choppy, and almost unplayable, even with the graphics set to their worst settings.

I do know that if my PC can't handle both, I probably need to upgrade hardware. But, before I spend $600 on a CPU (which I couldn't do; heck, I can't even afford Overture right now) or something, I wanted to see if there was another possible fix to make this work without spending a fortune. Is there another program, or is there some setting I can change that will allow this to work for me? If not, what hardware do you think would be high on the "upgrade" list?

My specs:

CPU: AMD Athlon 64 3700+
Video: nVidia e-GeForce 7800
Memory: 3GB DDR
Hard Drive space: 300GB on C, 200GB on D
Sound Card: Sound Blaster Live! 24-bit
Operating System: Windows XP Home Edition

Thanks in advance for any advice.