VT-x is not available. (VERR_VMX_NO_VMX) on windows 8

[windstory]

I've installed virtualbox on windows 8 x64, then when I open linux guest machine, I got this error message.


VT-x is not available. (VERR_VMX_NO_VMX).

E_FAIL (0x80004005)
Console
IConsole {db7ab4ca-2a3f-4183-9243-c1208da92392}

And as you can see the attached picture, I could not add cpus.

20121019_1_vm.jpg (112.21 KiB) Viewed 29877 times

Please let me know how to resolve this.

Thanks in advance.

[windstory]

It's my mistake.

I enabled hyper-v funtion. After disabling hyper-v, guest machine is loaded.

[michaln]

I enabled hyper-v funtion. After disabling hyper-v, guest machine is loaded.

Yes, that is the expected behavior (unfortunately) - if Hyper-V takes over hardware virtualization, VirtualBox can't use it.