You can check if the camera has been correctly installed by going to the Device Manager. Go to Start > Run > devmgmt.msc and locate the camera under the Imaging category. It should be identified as brand + model + webcam device. Secondly, go to Computer/My Computer and you should have the possibility to launch it directly from that location. Make sure that the camera is connected to the PC at all times while doing these procedures.
Another possibility is to use a chat application like Skype. It allows you to use your camera to video chat.