Archived from groups: microsoft.public.windowsxp.help_and_support (
More info?)
To fully remove Windows Messenger , close down Messenger if it's
running (right click the
messenger icon in the notification area/system tray and click close). Then
click the start
button, then click Run and type in (copy-paste if you like):
RunDll32 advpack.dll,LaunchINFSection %windir%\INF\msmsgs.inf,BLC.Remove
Then click OK.
Messenger will then be uninstalled.
For more detailed instructions and screenshots, go to,
http://messenger.jonathankay.com/problem.aspx?ID=7
Hope this helps