VT-x is not available (VERR_VMX_NO_VMX) - Hyper-V is disabled, VT-x enabled

[LexionTT]

Hello Community,

when I try to start a VM, following error occurs:

VT-x is not available (VERR_VMX_NO_VMX).

Fehlercode:E_FAIL (0x80004005)
Komponente:ConsoleWrap
Interface:IConsole {872da645-4a9b-1727-bee2-5585105b9eed}


Hyper-V is disabled on my machine:

HV.PNG (9.26 KiB) Viewed 10037 times

In BIOS VT-x options are enabled.

OS: Win 10.0.14393
VB: 5.1.2 r108956

On the start page, only Hyper-V is displayed as HW Support:

VB.PNG (4.65 KiB) Viewed 10037 times

Any ideas?

Thx

[Martin]

In another thread a user reported that he had to switch off VT-x in BIOS, start Windows, go back to BIOS and reenable VT-x to get it back working.

[LexionTT]

Switch off VT-x in BIOS, start Windows, go back to BIOS and reenable VT-x

Thx Martin for the hint. I've already tried this before. Didn't fix my issue.

[mpack]

You have to power off your PC (not hibernate) and then restart, in order for the CPU to start working in the new mode.

See this related topic: FAQ: I have a 64bit host, but can't install 64bit guests.

[LexionTT]

Tried this, but unfortunately it didn't resolve my issue.

Checked CPU state: Virtualization is enabled:

CPU.PNG (7.51 KiB) Viewed 10018 times

I can't explain the Hyper-V reference in the VM Settings pane.

VB.PNG (4.65 KiB) Viewed 10018 times

Are there any further ideas?

[mpack]

If it didn't resolve your issue then you didn't read it thoroughly enough. The FAQ lists all reasons why VT-x/AMD-v might not be available, and gives you a checklist to go through.

[LexionTT]

OK, checked 1) and 2) carefully.
Removed battery, restarted several times with different options, flashed BIOS etc.

How can I find out, whether another host application already uses VT-x?

[mpack]

Please post a VM log file. With the VM fully shut down, right click and "Show Log" in the GUI, save "VBox.log" (ONLY) to a zip, and attach the zip here.

[LexionTT]

Please see attached file:

W81Thin-2016-08-10-08-48-30.zip

(5.97 KiB) Downloaded 43 times

Thank you for your effort!

[mpack]

Unfortunately the log aborts before giving me the information I wanted.

Please tell me your exact CPU model as reported by "This PC".

[LexionTT]

Intel(R) Core(TM) i7-3740QM CPU @ 2.70GHz, 2701 Mhz, 4 Core(s), 8 Logical Processor(s)

CPU is definitely VT-x ready. With another Installation, 64bit VMs worked on this machine.

[mpack]

Yes, the CPU supports VT-x. Do you have any third party antivirus installed? If so, have you tried disabling it?

[LexionTT]

AV is Windows Defender. Deactivated Real-Time-Protection, but this didn't resolve the issue.
In another post, a possible cause is the activation of nested virtualization for Windows 10. I will try to find out how to check/disable the feature.

[mpack]

In another post, a possible cause is the activation of nested virtualization for Windows 10. I will try to find out how to check/disable the feature.

That only applies if Hyper-v is enabled, otherwise there is nothing to nest within. Also, the symptoms seem to be that VirtualBox thinks VT-x is available, but then crashes. That is not your symptoms.

[mhelbrau]

Just joined to post an answer, as I've been struggling with this too. It seems that after the RS1 update the Device Guard / Credential Guard is grabbing the VT-x process. This link: https://technet.microsoft.com/en-us/itp ... tial-guard has a section on removing it from your computer. It wasn't clear to me if it was either the group policy, registry, and bcdedit changes and/or the PowerShell script that were needed - so I did both with a final restart afterwards. Hope this helps.