Webcam help please?

[bobleponge]

Ok I have accepted that the webcam on my laptop is fubarred, but have bought an external one which works fine on Skype.
On Messenger however, it always defaults to the internal webcam, and I cant work out how to change this.
Does anyone know how I can use my external webcam on Messenger.
I think I use Windows 7? Its the one after XP anyway
Thanks in advance

[TEB]

On the Tools Menu in Messenger you should have a Audio and Video setup command, if you launch this you should be able to change the web cam on the second page of the wizard (usually).