virtualbox.org

I have a couple 64-bit guest VM that I was using on a i5 machine running Win7. I copied them over to i7 machine running a freshly installed Win8.1. The hardware I copied to actually has an older chipset i7, but according to the BIOS it does have VT-x and that VT-x is turned on.

However when I try and start them, I get "VT-x is not available. (VERR_VMX_NO_VMX)." error message.

A third VM that I copied over, with an ancient 32-bit Windows XP guest, runs fine. So I know I copied and set up the VirtualBox on the new Win8.1 system correctly.

I am running 4.3.10 and see 4.3.12 was just released yesterday, but nothing in its release nots seems related. I give it a try soon.

I will also try to create a new 64-bit guest machine to see if somehow only a previously created machine problem. But I really have to use the older VN as they have critical data and too hard to recreate.

Make sure Hyper-v is disabled on the host.

If you want to continue this discussion then post a VM log file. See Minimum information needed for assistance.

Thanks. That was the conflict. I knew I could not run two different hypervisors. But did not expect that simply having Hyper-V installed would prevent VirtualBox from running.

Do you know of a way to just turn Hyper-V on or off without having to go to "Programs and Features" and install/uninstall anytime I need to use it. Some registry item or simple script I could create?

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Lawrence

lwesker wrote:Thanks. That was the conflict. I knew I could not run two different hypervisors. But did not expect that simply having Hyper-V installed would prevent VirtualBox from running.

Do you know of a way to just turn Hyper-V on or off without having to go to "Programs and Features" and install/uninstall anytime I need to use it. Some registry item or simple script I could create?

--
Lawrence

you don't install and uninstall Hyper-V. You just enable or disable it.

lwesker wrote:But did not expect that simply having Hyper-V installed would prevent VirtualBox from running.

On Win8, Hyper-v runs by default at boot time. Your issue was not merely because Hyper-v was installed - if that was the case then merely disabling the service would not have fixed the problem.

I suggest you read up on the role of Hyper-v on Win8.