There should be an icon in your notification area(icons next to the clock) that looks like a network hard drive. Double click it and messenger should open. If it doesn't, double click the icon again while holding CTRL.
If messenger STILL won't open. In the task manager find the process msnmsgr.exe and click 'end process'.
To set a shortcut key to ensure you can open messenger next time, go to the top and click 'Plus!' then click options and preferences. In the pop up box click the 'messenger' tab and click 'Messenger lock' from the side tabs.(If you can't see it press ALT) Then, choose how you want to unlock messenger next time.
If messenger STILL won't open. In the task manager find the process msnmsgr.exe and click 'end process'.
To set a shortcut key to ensure you can open messenger next time, go to the top and click 'Plus!' then click options and preferences. In the pop up box click the 'messenger' tab and click 'Messenger lock' from the side tabs.(If you can't see it press ALT) Then, choose how you want to unlock messenger next time.