To upgradethe OS on the unit place the OS CD into the tray and shut the unit down. Press down the HOME and AUX1 upon startup until the unit says OS UPDATE..Release the buttons and wait for unit to ask you if you want to upgrade. Press Enter to begin upgrade. At this point the level meters will begin to fill up one by one. When all 16 meters are lit and flashing the the OS is done and you may turn the power off on the unit. Hold UTILITY upon startup to make sure the OS is on the correct version...once verified release and the eunit loads up as normal.