You’ve just created your first Generation 2 Virtual Machine using Microsoft Hyper-V and are ready to install Windows Server 2012 R2. You start up your VM and connect, preparing to boot to your mounted ISO.
You get to this point, where you’re ready to start your VM and install your operating system.
And then you encounter this error:
Now at this point, you follow the onscreen instructions and attempt to press any key. You quickly realize that nothing is happening and there is no way to load your ISO file. This error is only encountered with Generation 2 Virtual Machines.
Essentially, what you need to do fix the problem is to shut the VM down and then connect to it again. But this time, before you start the VM instance, make certain to hold down any key first, and keep it held down until the VM loads your ISO and prompts you to start the Windows 2012 R2 installation.
For more information on this issue, please visit: https://camerondwyer.wordpress.com/2014/05/05/solving-the-boot-failed-efi-scsi-device-error-when-installing-windows-2012-server-on-hyper-v/