Why is the Hyper-V add-on not enabled in Windows 8.1?

Question

Windows phone

There was a problem launching the Windows Phone emulator in Visual Studio 2012, 2013.
When I try to enable this add-on, I get the error "System cannot find the file specified. Error code: 0x80070002" during installation.
I did everything according to the instructions from - msdn.microsoft.com/en-us/library/windowsphone/develop/jj863509(v=vs.105).aspx, but to no avail.
Virtualization is enabled in BIOS, on my HP Envy4 laptop there is only one item that is responsible for this. The programs said that the processor supports all these necessary functions:
SLAT, EPT, VMX. During the installation / fixing errors, SDK 8.0 completes everything perfectly, all updates are installed at the studio.
System info with command msinfo32.exe:
Hyper-V - VM monitor MOde e... - Yes
Hyper-V - Second Level Address - Yes
Hyper-V - Virtualization Enabled - Yes
Hyper-V - Data Execution Protec..- Yes
And Hyper-V Virtual Machine Management is not visible in Services in System Configuration.

Answer 1

I decided to install clean Windows 8.1
Last time it was updated from 8.

Answer 2

Dism /Online /Cleanup-Image /RestoreHealth /Source: X:\Sources\SxS /LimitAccess
Have you tried it?
technet.microsoft.com/en-us/library/hh824869.aspx

Answer 3

Such crap, only my win 8.1 was a clean install. All tests showed that everything should work, and the emulator sins that low-level virtualization does not work for me, although it does.

Answer 4

In my case, as a solution to the problem, the installation of the Visual Studio service pack played www.visualstudio.com/news/2014-aug-4-vs