I just looked at your last post. You bought an "easycap". it is a fake. Save yourself any more hassle and bin the thing.
The newest model is ezcap116. As far as I know this has not been copied yet. I don't know where you live, but Google "ezcap116" and you will get a vendor that is selling the real product. It should come in a yellow and black box, with arcsoft showbiz and video blaze software. The vendor should also offer a 12 month warranty.
I have this model and I have tested in xp, vista and windows 7. The only problem i did have was with the USB sound on Vista but a quick fix is available.
Read here:
http://forum.easycap.co.uk/index.php/topic,109.msg916.html#msg916