When you got the webcam, you should have had a CD with the various drivers on it, failing that, go to the manufcturers website, they post new up-to-date drivers there all the time.

What I do, (and I wouldn't be too surprised if others do it too) is to create a folder in the My Downloads section just to save these into before you run them, that way you'll have a backup in case something goes south (by the way if you haven't got a My downloads Folder, just create one).

You could also do this with sound card, video card and chipset drivers.

It's worth a bit extra hassle to know you have at least a recent update isn't it?