uninstall / deactivate hyper-v? How?

[Kaiji]

I'm constantly trying to set up a virtual machine on Virtual Box 4.2 (Host Windows 7 Home Premium)
As I'm normally a Mac user my experience for Windows is a bit limited.
However every time I want to start (and install the new OS) i get this error

VT-x features locked or unavailable in MSR. (VERR_VMX_MSR_LOCKED_OR_DISABLED).

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

and

ID: HostAudioNotResponding

My first attempt was to repair Virtual Box using the install software.
Funny enough it asks me every time if I would like to install the USB-controller (which I've done now at least 20 times now )
So I guess something is prevent VB to install correctly.

Then I checked the internet if I'd find anything about Error E_Fail (0x80004005)
Apparently the most people facing this problem Updated they're Windows and that helped.
Didn't with me...

So I assumed it has to do with hyper-V "blocking" VB.
I tryed to deactivate or/and uninstall it with PowerShell, bcdedit and cmd - didn't work.

Now I'm out of ideas. I still suspect that hyper-V is causing my problem.
If so, how can deactivate or uninstall it?
If not, what is causing my problem and how can I solve it?

Thank's for every help.

[BillG]

What makes you think that Hyper-V is causing this? Windows 7 is not capable of running Hyper-V. Before Windows 8 it could only be run on the server OS.

There are several things which can prevent VirtualBox from accessing VT-x. The only way to find which one it is, is to methodically stop them one at a time until you find the culprit.