well... what operating system do you use? You have to find the Device Manager. If you use vista just go to search and type "device manager". If you're using XP, right-click on My Computer, choose Properties, go to Hardware tab and there is your device manager.
Now, one you open device manager, at Imaging Devices you'll find your webcam. Right-click on it and select Uninstall. Now restart your PC. When the PC reboots, it will search for the driver to install your webcam. If you use Vista or 7, it should find it on it's own, if not find the driver for the webcam and put it in the cd/dvd rom. you should manage from here. Restart again when install has finished and it should work just great