Shoutbox

If Chestah's method does not work you could add it to the registrys manually.

To do this go to start then run and type 'regedit'.

Then go to:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run

Then right click run and goto new>string and type 'MessengerPlus3'

Then right click the new string>modtify and type "C:\Program Files\MSN Messenger\msnmsgr.exe" /background

This should however all ready be there, but it may be worth checking.