New to vista and I need help with WMM?

I just got a new computer yesterday and it is a vista and I am confused. See I want to live tape a video rom my webcam to WMM(window's movie maker) but the only option I get is "Import from digital video camera" but when I click it and it says It can not find a digital video device. But is a webcam a digital vider camera? And also it will NOT let me make a live upload from my camera saying it is "not on" when my webcam does NOT turn on, it automaticly turns on when th compter tells it to. that is why it plugs in. So if anyone can tell em what I am doing wrong PLEASE do. Maybe I am just too used to windows XP