I installed all the prerequisites for Android development. I created a virtual device through Eclipse and tried to run the Hello World sample application in that device. I received the following error message.
emulator: ERROR: unknown virtual device name: 'Android21Device'
emulator: could not find virtual device named 'Android21Device'
I get the same error when I try to start the device from the command line and through the SDK program.
I can see the device directory and files at
D:\Users\anthony\.android\avd\Android21Device.avd