I was trying to install Windows Server 2012 R2 on my Virtualbox. On my first trial, I got an error that force me to shut down the virtual machine and seems there is no way to get Windows Server 2012 installed on Virtualbox. I am not sure why this happened and why I cant install Windows server 2012 on Virtualbox using standard method.
But fortunately, I found the solution for this problem. Now, I can install Windows Server 2012 R2 onmy Virtualbox without problems. After I created a virtual machine (VM), I will need to execute the following command before powering up the VM.
Open command prompt (in Windows) and execute this command
VBoxManage.exe setextradata “Windows server” VBoxInternal/CPUM/CMPXCHG16B 1
Change Windows server with your actual VM name. If your VM does not contain space, you can remove the trailing quotes before and after the VM name. After this command, you can start or power on your VM and now you should be able to run Windows Server on VirtualBox.