This was very irritating that you couldn't have the icon in the tray for
live messenger running on windows7, but I found the solution and I blogged
about it to share this trick.
Problem:
One of the most annoying things when I started using windows 7 Beta 1 and
the freshly released Live Suite (messenger, writer, mail etc) was that the
live messenger icon was not always visible in the tray like it used to be in
XP and Vista, rather it always had an entry as a button on the taskbar.
http://computerboom.blogspot.com/200...nger-tray.html
Find solution in the above link