For those that auto-install MSN Messenger, I have written this registry tweak which stops it from setting 'Open Messenger main Window when messenger starts' on by default. Turn off 'show Main Window' REGEDIT4 [HKEY_CURRENT_USER\Software\Microsoft\MSNMessenger] "AppSettings"=hex:08,93,01,80 Turn on 'show main window' REGEDIT4 [HKEY_CURRENT_USER\Software\Microsoft\MSNMessenger] "AppSettings"=hex:28,93,01,80