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Why is the hypervisor running even after I uninstalled Hyper-V? RRS feed

  • Question

  • Hi Virt experts,

    I'm running into a weird issue on my Lenovo Z51 laptop and was hoping to find help. The laptop is equipped with an intel i7 processor, supports VT and SLAT, and is running Windows 10 Pro 1607 (Build 14393). I had Hyper-V installed on this laptop with all kinds of VMs running for a while. Then I got a VMware license and decided to uninstall Hyper-V so I can install VMware.

    I uninstalled Hyper-V by going to "Turn Windows Features on or off", unchecking all options under Hyper-V and then rebooting the machine on the prompt. After the reboot, I went to "Turn Windows Features on or off" again and confirmed all options for Hyper-V is unchecked. However, when I look at msinfo32 it still says:

    >> "A hypervisor has been detected. Features required for Hyper-V will not be displayed." <<

    Coreinfo.exe says the same thing:
    Intel(R) Core(TM) i7-5500U CPU @ 2.40GHz
    Intel64 Family 6 Model 61 Stepping 4, GenuineIntel
    Microcode signature: 00000021
    HYPERVISOR      *       Hypervisor is present <---------
    VMX             -       Supports Intel hardware-assisted virtualization
    EPT             -       Supports Intel extended page tables (SLAT)

    I had already tried the below steps assuming it may be some hyper-V component corruption or bad CBS state:
    "SFC /scannow" & reboot,
    "dism /online /Cleanup-Image /RestoreHealth" &  reboot

    I even downloaded the 1607 ISO and did an in place upgrade on the same machine. Even after the upgrade - the hypervisor shows it is still running. I did some hunting, seems no one have tried this on 1607 so far. Folks from the Windows Server forum redirected me here:

    https://social.technet.microsoft.com/Forums/windowsserver/en-US/8a1f9ba3-9d6b-439a-99a7-f2c318169f9c/why-is-the-hypervisor-running-even-after-hyperv-is-uninstalled-?forum=winserverhyperv#5c625896-9640-4f91-a49c-133b09a127c5  

    Why does it say the hypervisor is present when I have uninstalled Hyper-V ? What can I do to fix this and run VMware ?


    Vimal

    Thursday, December 22, 2016 11:49 AM

Answers

  • I'm not sure why your install says there is a hypervisor present as I haven't seen this problem.  There is a question of Visual Studio enabling Hyper-V it in some cases, but I haven't ever seen why.

    It's possible the Hypervisor running isn't Hyper-V's hypervisor, but if it is, this command from an elevated command prompt should disable it so you can test that. Other possibilities for a hypervisor is the Hyper-V hypervisor running Credential Guard, or malware.

    BCDEDIT /Set {current} hypervisorlaunchtype off

     


    Bob Comer

    • Marked as answer by VimsShek Thursday, January 5, 2017 12:04 PM
    • Unmarked as answer by VimsShek Thursday, January 5, 2017 12:10 PM
    • Marked as answer by VimsShek Thursday, January 5, 2017 12:10 PM
    Thursday, December 22, 2016 1:53 PM

All replies

  • I'm not sure why your install says there is a hypervisor present as I haven't seen this problem.  There is a question of Visual Studio enabling Hyper-V it in some cases, but I haven't ever seen why.

    It's possible the Hypervisor running isn't Hyper-V's hypervisor, but if it is, this command from an elevated command prompt should disable it so you can test that. Other possibilities for a hypervisor is the Hyper-V hypervisor running Credential Guard, or malware.

    BCDEDIT /Set {current} hypervisorlaunchtype off

     


    Bob Comer

    • Marked as answer by VimsShek Thursday, January 5, 2017 12:04 PM
    • Unmarked as answer by VimsShek Thursday, January 5, 2017 12:10 PM
    • Marked as answer by VimsShek Thursday, January 5, 2017 12:10 PM
    Thursday, December 22, 2016 1:53 PM
  • Thanks Bob,

    I had seen many folks use hyper-V and VMware workstation in parallel by setting the "hypervisorlaunchtype" to off whenever they needed VMware to work. But in my case - setting "hypervisorlaunchtype" to off and rebooting - still didn't stop the hypervisor. This was the main reason why I decided on removing hyper-V from the machine in the first place. I have uninstalled VMware, so currently on my machine both VMWare and hyper-V are not present. I have the "hypervisorlaunchtype" set to off in my BCD and the registry shows it too: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control - SystemStartOptions key shows: "FLIGHTSIGNING  NOEXECUTE=OPTIN  HYPERVISORLAUNCHTYPE=OFF". Yet - msinfo32 still shows the same message.

    >> "A hypervisor has been detected. Features required for Hyper-V will not be displayed." <<

    I do have Visual studio 2013 and 2015 installed as this is my primary work laptop. I'll check regarding credential guard.


    Vimal

    Thursday, December 22, 2016 2:21 PM
  • Wow, guess what - Credential guard appears to be enabled:

    > Get-ItemProperty "HKLM:\SYSTEM\CurrentControlSet\Control\DeviceGuard"

    RequireMicrosoftSignedBootChain   : 1
    EnableVirtualizationBasedSecurity : 1
    RequirePlatformSecurityFeatures   : 1

    So that must be why hypervisor is still running. I found steps to disable it in : https://technet.microsoft.com/en-us/itpro/windows/keep-secure/credential-guard?f=255&MSPPError=-2147217396 But it looks cryptic. I'm not sure how to get to the EFI partition from within the OS. I'll try researching a bit more, and then attempt to disable credential guard.  


    Vimal

    Thursday, December 22, 2016 2:30 PM
  • Interesting!

    I don't really know anything about Credential Guard, so I'd be interested in how you get things straightened out!


    Bob Comer

    Thursday, December 22, 2016 3:19 PM
  •  Hi Bob.

    I don't know anything about it either, but apparently it is only available for Enterprise versions of the OS running under AD. And it uses VT-x for virtualization-assisted security.

    https://www.petri.com/windows-10-enterprise-feature-credential-guard


    Bill

    Thursday, December 22, 2016 11:17 PM
  • Saturday, December 24, 2016 10:27 PM
  • Thanks guys, once I disabled the virtualization based security used by credential guard - that disabled my hypervisor. I was able to get the VMware workstation installed and the VMs are running.

    This article has steps:

    https://technet.microsoft.com/en-us/itpro/windows/keep-secure/credential-guard?f=255&MSPPError=-2147217396

    I preferred to use this "Device Guard and Credential Guard hardware readiness tool" instead. Its a powershell script that checks to see if your machine is ready for device guard. The script has switches to enable and disable device guard.

    Here's a link to the tool:https://www.microsoft.com/en-us/download/details.aspx?id=53337


    Vimal

    Thursday, January 5, 2017 12:14 PM
  •  Thanks for the follow-up.

      All the steps you did earlier did not solve your problem because it was not Hyper-V or its hypervisor causing your problem.


    Bill

    Friday, January 6, 2017 1:51 AM