cannot get to audio video setup

Please help. I have a PC with a motherboard that does not have a bios that
can be upgraded for SP2 compatibility; I therefore have XP with SP1. This
means that I use Live Messenger 8.1 in compatibility mode for Windows 2000 to
prevent the message asking me to upgrade whenever I try to connect. This
results in the problem that I cannot get to the audio video setup in Live
Messenger so cannot use my Webcam with Messenger. If I remove the
compatibility mode tick, I can then get to audio video setup. However, as
soon as I change this back again I am back to square 1. Is there a fix for
this? Is there any way to stop the prompt to upgrade to a later version of
Live Messenger without having to use compatibility mode?