Found this over on MSN Fanatic ...
Bunnios has managed to rip Messenger 4.7.0036 from the latest Windows XP SP1 beta... and it's up on Heavy K's site...
It works for ALL versions of Windows (heck even Windows 95 :D )... And as usual I'll not offer the usual warnings, just enjoy...
News source: Heavy K's Hangout ...
Download: Windows Messenger 4.7.0036
View: Heavy K's Polygamy patch for Messenger 4.7.0036 (Allows multiple instances of Messenger to be run)
This is BETA software!, please use caution when installing it on your system.