Error 21 - The device is not ready.

Created by Jeff B on on 2012-03-26

If you're getting any indications that the device is not ready, there is probably some process preventing WinImageWriter from getting an exclusive lock on the device. Make sure that any program accessing the device is closed. This includes Windows Explorer, which means that any explorer window showing the contents of the device will prevent WinImageWriter from being able to write to the device.