VirtualCoffin

[hgm]

Lately I have been doing all my development work on Linux, running Ubuntu in VirtualBox on my Windows 8.1 host. Unfortunately, as of today, this ceased to work. When I try to boot a VM, I get the dreaded VERR_VMX_NO_VMX error, telling me that VT-x virtualization is not available.

When I start the BIOS, it tells me that virtualization is enabled.

When I try to disable Hyper-V, (mentioned as another common cause for this problem), it cannot be found (it is not in the features list, if I use dism.exe from the commont line it is says it is an unknown feature). So I suppose I don't have this at all, which should be as good as having it disabled.

The final common cause for this seems to be that the CPU doesn't support virtualization. Which seems unlikely, since I have been using it for years on that laptop.

Does that mean my CPU is now broken? Or can anyone still think of another reason for this behavior? If the CPU is broken, is there a way to rescue the file system of the VM, so I can port it to another machine?

[flok]

You could convert it to vmware and then use the free vmware player.
https://www.maketecheasier.com/convert- ... irtualbox/

[syzygy]

Is Hyper-V enabled? Then disable it.
https://forums.virtualbox.org/viewtopic.php?f=6&t=52191

[syzygy]

I wanted to say Hyper-V, but you've already mentioned it. (Hmm, and I thought I was editing my previous comment but somehow I added a new one.)

I don't know much about Hyper-V, but it seems it is available on Windows 8 (but maybe not on all versions?).

[hgm]

It doesn't appear in the list of Windows feautures. Neither in the dialog for enabling / disabling them, nor when the list is requested with the aid of the dism.exe from the command line. So I can only conclude that it must be an optional feature, and that I don't have it installed.

[pferd]

Maybe you can check if you are running the latest version of virtualbox and update your installation.

If that does not help I would export the Vbox-Image to another machine and see what happens

https://superuser.com/questions/633431/ ... r-computer

[Sesse]

I suppose you've verified that VT-d is enabled in your BIOS/UEFI settings?

[noobpwnftw]

Do you happen to install Intel HAXM(that comes with Android Studio install) or any antivirus software that uses VT based sandboxes?
One quick way to find out might be to disable VT in your BIOS and see if something else complains about lacking VT support.

[Joost Buijs]

It is very likely that a Windows update broke something in the Virtualbox you are running. On the 18th Microsoft issued several patches for Windows 8.1 (KB4338831). https://support.microsoft.com/nl-nl/hel ... thlyrollup

When you have this update installed you could try to uninstall it. Also make sure that you have the latest version of Virtualbox installed.

I don't think Windows 8.1 has Hyper-V installed by default, but disabling the launch of hypervisor with bcdedit is something you can try. In an elevated console window type "bcdedit /set hypervisorlaunchtype off".

[hgm]

Thanks everyone for the advice. As an immediate emergency measure I did the export-import trick to bring the VM to my desktop. The .ova file was only 3GB, and fitted on one of my memory sticks without problems. That restores my ability to access my web servers through ftp and ssh (which for some reason doesn't work from Windows), which was the most urgent problem.

When I have a bit more time I will try some of the other suggestions to see if I can revive the thing on my laptop.

Thanks again!