This depends on how your camera is recognized by your computer when connecting it
through an USB port;if your computer sees it as an extra drive and adds a letter to it so you can access
the *jpg-files on it via Explorer or Total Commander (Or any other filemanager) then it probably won't work as a webcam.
If you need to retrieve your photos from your camera via an application included on the CD-rom,then it works
via the scanner-protocol where you "Acquire" your photos through a driver program and into your application,then
it will also work as a webcam,and MsMessenger or any other chat-progr. will probably immediately recognize it as a webcam...