Installed Visual Studio, cant get rid of hyper V (i think)

[takigama]

So I had a nicely working virtualbox (5.0.22) on my windows 10 box, then (as far as i know) the only change i'd made was to install Visual studio 2015 (community).. since then i've been unable to boot any virtualbox hosts with:

Code: Select all

Failed to open a session for the virtual machine svrpbox.

The VM session was closed before any attempt to power it on.

Result Code: E_FAIL (0x80004005)
Component: SessionMachine
Interface: ISession {7844aa05-b02e-4cdd-a04f-ade4a762e6b7}

And sure enough in the logs:

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00:00:01.694071 
00:00:01.694072 ********************* End of CFGM dump **********************
00:00:01.694081 VM: fHMEnabled=true  (configured) fRecompileUser=false fRecompileSupervisor=false
00:00:01.694083 VM: fRawRing1Enabled=false CSAM=true  PATM=true 
00:00:01.694675 VMSetError: F:\tinderbox\win-5.0\src\VBox\VMM\VMMR3\HM.cpp(576) int __cdecl HMR3Init(struct VM *); rc=VERR_VMX_NO_VMX
00:00:01.694699 VMSetError: VT-x is not available
00:00:01.870917 ERROR [COM]: aRC=E_FAIL (0x80004005) aIID={872da645-4a9b-1727-bee2-5585105b9eed} aComponent={ConsoleWrap} aText={VT-x is not available (VERR_VMX_NO_VMX)}, preserve=false aResultDetail=0
00:00:01.871152 Console: Machine state changed to 'PoweredOff'
00:00:01.896075 Power up failed (vrc=VERR_VMX_NO_VMX, rc=E_FAIL (0X80004005))

Which normally suggests either hyper V has been turned on or VT is turned off in the bios (which i've checked and is correct). Hyper V was indeed installed when Visual studio was installed, but im fairly certain i've removed it by:
1) removing it as a feature in "windows features"
1.1) also with "dism.exe /Online /Disable-Feature:Microsoft-Hyper-V-All"
1.2) and also with "Disable-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V-All"
2) disabling any service that hints about being a part of hyper v
3) uninstalling any software that came with visual studio that sounded like an emulator or similar
4) disabled it in the boot with "bcdedit /set hypervisorlaunchtype off"
5) numerous reboots
6) re-installed vbox a number of times (including the latest stable version).

Only complication i can think of is that its a dual boot laptop and windows gets booted from grub and there are vague posts here and there stating bcdedit has issues if your booting via grub (though nothing concrete as such)

Anything i might of missed here that might also cause virtualbox to fail to get the vt hardware bits it needs?

[SchweizerGarde]

Hi takigama,
I do have the same problem here with a plain vanilla W10 Professional as host. After installing VS 2015 I get exactly the same error when trying to launch any guest, even DOS.

[Martin]

You need to find out what is changed by VS2015.
Hyper-V, Device Guard and Credential Gueard all activate VT-x at boot so nothing else can use it at the same time.

[socratis]

Just for completion: KB 3204980: Virtualization applications do not work together with Hyper-V, Device Guard, and Credential Guard.