Ok I think I've figured it out with the help of a computer savvy friend. The computer is shutting off the DVD drive to save power. We went to Acer website and downloaded the Power Smart driver for Windows 7. If the laptop is plugged in when started up, the DVD drive does not disappear. If you're on battery power, you need to go into the power options on start menu and change the settings under balanced power. Otherwise, on battery power, the DVD drive gets shut down to save power. So, if you change the settings, you can at least press the eject button and the DVD drive will pop out to use (under battery power). If you're going to use the drive for a long time, like I will when I record music from a keyboard onto my laptop and burn CD's, use the power cord.
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