Best *free* webcam recording software

I'm trying to set up a discrete video surveillance using my laptop to catch someone red handed.

I only use a fraction of the software built into Windows 7. If it were not for flash memory and wireless support, I would still be using Windows 2000 professional. Is there anything built into Windows 7 starter that would do the job at recording from a webcam?

What I am looking for is something I can set the bitrate low enough so I can record up to 12 hours if necessarily and turn the sound off to save on disk space.

I know I can probably find something on Tucows or CNET which usually requires downloading, installing and removing 10 programs before finding one that even works.

Just wondering if there is something any of you have used that works well. I don't want to sound cheap but this isn't something I plan on using frequently so it would be cool if it's freeware.

Thanks.