Cannot Find Camera Error with blank screen

After performing a restore to factory settings on my computer, I cannot get my webcam to show up in the device manager even after installing all the drivers multiple times. During the first month I had the laptop, everything was fine until it disappeared suddenly. I keep getting a message "Cannot find camera" with a blank screen. My webcam doesn't even show up in the device manager. The microphone does work. This is built-in webcam for Toshiba Portege R705-P25 (Windows 7) I need help.
