First of all, are you 100% sure its a video in? Alot of cards have s-video out not many have video in.
If it is video in, your video card should have come with some sort of capture software.
some, like eVga, require you to register the product before they send you the software you need.
If it is an nVidia card you can download the drivers from www.nvidida.com (capture drivers) and use windows movie editor (if you have xp or me) to view the images.
If it is ATI (like an all-in-wonder) the capture should be part of the driver already installed, if not download the latest from Ati, as well as the Multimedia Center to view the images.
