help with logitech quickcam & XP

[Ellie]

whenever i load my webcam up, it says that there is a
problem with it and i can't use it.
i did all the usual reloading of discs and XP and etc and
it still said the same.
So i bought a new webcam and got the same.
I thought it might be my USB ports, but they work fine
for other things.
help!