I was able to switch the webcam on by pressinf fn+f7, but all this has done is switched on a little ble light next to the webcam lens at rop of my screen.
I still do not know how to find and activate the webcam!
There is often no special software installed for a webcam as they are meant to be used with other software that supports webcams, such as skype and MSN messenger.
Try looking in computer and see if there is a camera icon there, if you really can't find anything to do with the cam then the link below is free software that should let you view the output from the camera and take pictures/videos with it.