Error "VT-x/AMD-V hardware acceleration not available on your system" while trying to run Virtualbox

I have to run Mac OS on virtual box for a class and it keeps giving me errors stating

"VT-x/AMD-V hardware acceleration not available on your system. Certain guests (e.g. OS/2 and QNX) require this feature and will fail to boot without it."

If there is a solution, I am not used to windows 8.1 and will need detailed instructions on how to fix it. Thank you

You don't have to uninstall/reinstall HyperV

I ran into this same issue using the new Visual Studio 2015 Android emulator and Windows Phone emulator, while also trying to run VirtualBox clients. Unfortunately you can't run VBox at the same time as the other emulators; you just have to setup a new boot option and reboot to switch back and forth.

Open an administrative command prompt and run:

C:\>bcdedit /copy {current} /d "Windows w/ HyperV"
C:\>bcdedit /set hypervisorlaunchtype off

This will copy your current boot settings to a new boot option called "Windows w/ HyperV" and then will disable HyperV under your current boot option. You can run "bcdedit" with no parameters to check that {current} has the hypvervisorlaunchtype set to "off" and that the new section has hypvervisorlaunchtype set to "auto"

See Scott Hanselman's article for more information.

Do you have Hyper-V installed? For example it may have been added if you installed the Windows Phone emulators which come with Visual Studio 2012 & 2013.

If so, then there is a known conflict between Hyper-V and VirtualBox - Hardware Virtualisation support not detected if Hyper-V installed.

A similar problem occurs trying to use Intel HAXM to accelerate Android x86 Virtual Devices - Windows 8 - How to install Intel HAXM after installing Hyper-V.

Uninstalling the Windows Phone emulators and turning Hyper-V off in Control Panel >> Programs and Features >> Turn Windows features on or off seems to be the only workaround for the moment.

For anyone else who may look this up in future. I had the same problem. Turns out virtualization had been disabled in the bios. Check if this is the case. If so, just enable it and the error is gone