virtualbox.org

I want to install Windows Server 2012 on a VM.
I am running Windows 7 64-bit.
It is an AMD Athlon XII 255, with 4MB RAM and 500GB HDD.
Nvidia GeForce 630 GPU / GeForce 7025 GPU.
I have done the initial 'New' settings in VirtualBox, but when I go to install it, I get the following error message:

VT-x/AMD-V hardware acceleration has been enabled, but is not operational. Your 64-bit guest will fail to detect a 64-bit CPU and will not be able to boot.

Please ensure that you have enabled VT-x/AMD-V properly in the BIOS of your host computer.

What does this mean?

It means what it says. VirtualBox cannot run 64bit VMs unless VT-x or AMD-v is available, i.e. hardware support for virtualization. Of course to be available it must be supported by the host CPU, and VBox is telling you that's the case, it must be enabled in the host PC BIOS, and nothing else can be using it (e.g. Hyper-v).

I thought I'd let you know I enabled 'Secure Virtual Machine Mode' in my BIOS, and now the VM works perfectly!

Thank for coming back and give the resolution of your issue. That was the right option indeed, even thought the name is not alaways obvious at all, like in your case.