How to Fix Windows Server 2012/Windows 8.1 installation Error Code 0x000000C4 in VirtualBox

When you have an iso file of Windows Server 2012 or Windows 8.1 and want to install it on VirtualBox, maybe you will get an error Error Code 0x000000C4. So I got the same problem when trying to install Windows Server 2012 on VirtualBox. With VirtualBox, you can get a ton of this kind errors. And today I will show you how to fix Error Code 0x000000C4 in VirtualBox.

1) The first thing you need to do is open up a command prompt(cmd) on your computer. And make sure you have closed all VirtualBox processes in your computer.
2) Now type in next command to get a list of your virtual machines.

"c:\Program Files\Oracle\VirtualBox\VBoxManage.exe" list vms

Now from list copy the name of your Windows Server or Windows 8.1 where you get an error when trying to install it.
3) After you need to execute next command:

"c:\Program Files\Oracle\VirtualBox\VBoxManage.exe" setextradata "virtual machine Name" VBoxInternal/CPUM/CMPXCHG16B 1

Change the "virtual machine Name" from command with the name of your virtual machine which you have copied in the previous step. Write name with double quotes.
Now close the command prompt and open the virtual machine. Try try to install operating system again and you will no get any 0x000000C4 error anymore.