Unable to create 64-bit Windows guests (on 64-bit host)

[pan_vb]

Host is Windows 7 64-bit with 8 GB of RAM on a Lenovo with an i7-3520 CPU. No problem with 32-bit Windows (XP, Vista and W7) or Linux guests. But I've tried 64-bit W7 and Vista guests and get a blue screen every time. I've checked the BIOS of the host system and the virtualisation options are all set. I've changed memory, CPU and just about every other option I can think of on the guests but it makes no difference. Where do I go next?

[mpack]

To run a 64bit guest you need VT-x, regardless of the register width of the host. Your CPU appears to support it, so you just need to ensure that it's available: enabled in the BIOS, enabled in the VM settings, and not already in use by something else.

[pan_vb]

Your CPU appears to support it, so you just need to ensure that it's available: enabled in the BIOS, enabled in the VM settings, and not already in use by something else.

It's enabled in the BIOS and the VM settings. How do I check if it's in use by something else?

[mpack]

If VT-x is available then VirtualBox's New VM wizard will include 64-bit templates. Pick an appropriate one.

If it doesn't work then post the VM log file as a zipped attachment. The VM log file is called "VBox.log" and can be found in the "Logs" subfolder of the VM folder. Make sure the VM is shut down before you zip up a copy.

The only reason it would be enabled in the BIOS but not available to VirtualBox would be if you had other software running which already uses it. E.g. another VM platform, a debugger of some kind etc. Only you can know what you installed.

[pan_vb]

Thanks. The host did have XP mode installed - but I uninstalled that so as far as I know there's no other virtualisation platform or layer active. The right templates are offered. I virtualised a working 64-bit machine and tried to open that in VBox but that blue screens as well.

Log file attached.

[mpack]

What is the error message on the blue screen?

I also notice that the VM is called "Old Vista Laptop". Is this a P2V project? If so then it would have been useful to mention it. I see that the disk type is VMDK, if it's a P2V project then how was the VMDK created?

[pan_vb]

I did say in the previous message that I had virtualised an existing system - in this case to short circuit the build process in the hope of isolating the problem. The blue screen is giving a stop error of: 0x0000007B. This is inaccessible boot device. The system was virtualised with an IDE hard drive, which is what I set it to be in VBox. It's a VMware 6.0x format vmdk file, if that helps.

It was converted using Vmware's vCenter Converter. I've used the same process frequently on 32bit systems and it's been fine.

[mpack]

Stop 0x7B is a common one on a P2V project. It means a disk error: it can't find the expected disk controller or partition needed to boot the VM. Try setting the VM to use an IDE controller.

[pan_vb]

I have, and I've tried all three types. The furthest I've got is the splash screen, the option to boot into safe/safe with prompt/normal modes and then the blue screen. As I said, I've not had the problem with 32bit machines, only 64bit.

[mpack]

The disk controller is agnostic: it doesn't care if you install a 32bit or 64bit OS. I suspect your problem is with how Windows Vista+ finds the hard disk. The best fix is probably to boot the VM from the Vista setup CD/DVD and repair the installation. Make a backup of the VM before trying it.

[pan_vb]

Thanks for the help. In the end I went through and tried every disk controller in turn. Despite the vmx file stating that the VM had an IDE drive, it was when I used the VBox SCSI controller that I managed to boot it. Now it's the usual fiddling to install the right drivers and so on, but for now it's no more blue screens. Thanks again.

[mpack]

The VMWare VM likely had two disk controllers, SCSI and IDE, the latter used for the CD/DVD drive.