virtualbox.org

hi to all. i have host at 2008R2, my motherboard and CPU support hardware virtualization, this server have instaled role hyper-v and it can create any x64 os. then why virtual Box don't give me create any x64??

Why mention Hyper-v? The presence of Hyper-v would mean that you can't create 64bit guests, not that you can. Hyper-v is a competing VM platform, and you can't have two VM platforms running at the same time if they both need VT-x.

you can't have two VM platforms running at the same time

it's wrong, i have at the same time running hyper-v and virtualBox VM and there no errors of compatibility. i have mention about hyper-v as proof my hardware satisfy virtualization and 64 bit too. on screenshot you can see i have not x64 versions of OS. where is problem??

If you're running Hyper-V, it means that Hyper-V has taken over hardware virtualization and no one else, including VirtualBox, can use it. And VirtualBox requires hardware virtualization for 64-bit guests.

So it's great that hardware virtualization works on your host, but if you allowed Hyper-V to use it, you at the same time prevented VirtualBox from doing the same.

so, you mean i can use 32 bit guest on hyper-v and virtualBox at the same time but 64 bit not, right??

I know this is an old thread, but I was looking for the last couple of weeks for a solution to my issue on my laptop.

I've just managed to fix this issue on my laptop. I had both Virtualbox and Hyper-V running. Virtualbox would only recognise one processor instead of the four in my machine. Once I uninstalled Hyper-V, Virtualbox functionality was brought back (multiple cpu/core).

Based on this, I would suspect you can run 64bit os's in hyper-v and only 32bit os's in virtualbox at the same time. Hyper-V reserves the VT-chip portion and won't allow other programs access to it. Disabling the Hyper-V service won't work - you have to uninstall it.

You don't have to uninstall Hyper-V. You do have to make sure that the hypervisor does not load if you want to use VT-x.

You can do that from BCDEDIT. Change the hypervisorlaunchtype from auto to off.