Go to the creative website and download the latest drivers for your webcam.
Begin by installing the drivers first (do not plug the webcam in yet. Then switch off the PC and connect the webcam. Windows will identify it and finnish installing the drivers (a notification comes up in a ballon).
Once you have done this install any software that came with the webcam, of any downloaded.
Should this cause a problem, sometimes rebooting can solve it.
If you mearly plug the cam in and then install software windows would often start to install its own before the webcam software, this can cause a conflict with drivers.