Capturing High-res output from video card

[wolrahnaes]

I am currently using my ATI All-In-Wonder card recording the S-Video out from another PC to get screenshots before the OS is loaded. This is not very high quality, and I would like better.

Is there any way to hook the monitor output from one PC to an input on another?

DVI input would obviously be preferable for quality reasons, but VGA is still usable. Component video (HDTV YPrPb) is even an option, as I plan to get a Radeon card that supports HD output.

Google searching for "DVI Input" resulted in nothing but HDTVs