Shoutbox

if it's a big name webcam (logitech, microsoft, etc) then there'll probably be some kind of software studio you can download for creating videos

if not then windows movie maker can record direct from webcam

or alternatively use the webcam preview window (Found in My Computer) and then use a screen recorder such as Bulent screen recorder......or any other free one (a quick google search for "free screen recorder" will turn up plenty of results)

hope this helps