The webcam software on my Toshiba P200 seemed to be a bit temperamental: the built-in cam (Chicony USB) wouldn't start when trying to start a video conversation on MSN and attempts to configure it gave messages which said it wasn't connected.
I cured the problem by going into the windows Vista control panel, opening the Device manager, opening the Image devices folder and uninstalling the Chicony USB camera. I opted not to remove the driver just in case I couldn't get it back again from Internet.
After rebooting, the web camera software, a toolbar that comes out of the left-hand side of the screen when you move the mouse there, now seemed to function. The buttons seemed to work OK (they didn't before or were temperamental).
On my computer you can also start the software by going into Start / Programmes / Camera Assistant. No idea who the software publishers are.
Whether or not this software is running, I can start my webcam using the [Alt] - [F7] shortcut mentioned in the software's help pages.