Yes, if you have a microphone and a webcam connected to
your computer, you can use messenger to set up audio
conversation or video conversation (with audio). It is
very simple and easy to use if your computer is connected
to your Internet Service Provider (ISP) directly.
However, if you have a home network and have a router
installed between your cable moderm and your computers,
it will become a bit complicated because you will have to
know how to change your ports setting in your router to
allow voice signals go through your router to one of your
computers in your network. Otherwise, you can only send
text messages and you won't be able to use messenger to
make phone calls or have audio/video conversation. Visit
the following website for more information if you have a
NAT device installed:
http://support.microsoft.com/?kbid=324214
Good luck.