Built in webcam disappeared

Hi, i own a asus eee pc netbook which has a built in webcam. This was working fine, but now as i go to view it in my computer there is no icon for it. There is also no webcam icon on msn. We tried to download the device scanner but to no avail. Could anybody help me please iin this matter (intermediate pc user).
Thankyou
Windows123

go into device manager by right clicking on my computer/manage/device manager look and see if there is any devices that have a yellow explination mark next to them, if so righ click and choose reinstall drivers. The other option is click on imaging devices below that you should see the webcam right click on it choose uninstall and reboot. when the pc reboots it should reinstall the webcam automatically, if not you will need to browse to the location of the drivers you downloaded