If you are seeing the error below, you must go to your Altitude directory (in this case, C:\Program Files\Altitude) and delete the update directory. You should then be able to run the game without any problems.
Code:
Launcher Error - File Lock Detected
Failed to update file:
C:\Program Files\Altitude\launch.jar
This file is probably in use by another application.
Close all applications that may be accessing this
file and try again.
Try again? [Yes] [No]
This should only effect people who tried to update at 6PM EST on October 22nd -- sorry guys, I screwed up!