Have you tried
THIS link?
Seems you are not entirely alone, although just about everyone is happy with it. Apart from Mac users, obviously (JOKE). A user here reports:
This cam is (almost) installed to a Phenom II Hexcore system running Windows XP with SP3.
It says on the box that supported systems are Win XP (SP2+) Vista and Windows 7.. but the supplied CD does not cleanly install the software to Windows XP.. However, a visit to Microsoft Website accesses and freely downloads a more recent version of the software that is more Windows XP friendly, and a successful installation of the driver software followed.
Forgot to mention, click on the Support tab.