i don't qutie agree with youmajority of windows xp users are using MSN messenger, rather than windows messenger. it runs on windows XP without any problem.
in fact in the MSN messenger download page , windows XP is the first in the OS list.
windows messenger is a build-in .NET service in windows XP. but it doesn't mean it's by any means the "official MSN client" in windows XP. (more...)
Well... I haven't been keep track with MSN Messenger.
As a matter of fact, its previous version does distinct "MSN Messenger" and "Window Messenger" as recommended for different platforms. But confusions among user have somehow forced them to name both versions the same now. Sorry for the confusion created by my remarks.