Windows Live Messenger 2009 has a number of Command Line Parameters available that you can use to start actions within Messenger without opening it up.
You can use these for a variety of purposes, like scripts, hotkey/macro applications and anywhere else where you can start a program.
Parameter : Action
/available : Sets your status to available (online)
/busy : Sets your status to busy
/away : Sets your status to away
/invisible : Sets your status as appear offline
/sendim : Opens the “Send an instant message” window
/msn : Opens the MSN home page
/email : Opens your Hotmail inbox
/profile : Opens your Windows Live profile
/signoutal : Signs you out of Messenger from all logged in computers
You can use several at once too, the actions will be executed in order.
How to use parameters:
If you’re not familiar with adding parameters, to use these you’ll need to append the parameter to the end of starting the Messenger executable. For example, pop open the Run dialog by pressing the Windows key and R (or click Start then Run on XP, or in Vista/7 click Start and type in the search field at the bottom.
Then type msnmsgr /busy and click OK. Now your status will switch to Busy within a few seconds.