Windows vista cannot rec real time video.

using sightspeed for video chat. one end [win2000sp4 updated] working fine. other end winvista [newbe at that end] cannot rec video but both can hear. Streaming video [real time video-voice chat] in vista isnt working. Has quest dsl as isp. Cant see themselves when recording either within sightspeed. Its vista problems and settings but dont know where to look or what to look at. Monitor is fine and all else is working. I can see them but they cant see me and I can hear them and they can hear me. SightSpeed says its the vista display is the problem. [maybe-I think]