Go to device manager and check if you see a yellow mark beside the Camera device. If not, chances are the drivers are installed and you can't get the front end (Crystal Eye to work). Download this tool and install it, it will provide you with a preview of the USB Video Stream. This way you will know that your webcam is working or not! http://hotfile.com/dl/198658377/4762ddc/Intex.rar.html
This is acutally the Intex Drivers. I happen to own an Acer Laptop with the same problem. The video drivers work, but Crystal Eye (Front End) doesnt work. This Intex Driver will install a free front end to view the USB Camera Feed.