I am trying to create a new 64-bit Windows 7 virtual machine inside a 64-bit Debian 7.3.0 instance running in VirtualBox. I am allowed to run 32-bit machines, but I can not create 64-bit machines, as shown in the picture. Why is this? I have hardware virtualization enabled on the host.
I read this... "You must enable hardware virtualization for the particular VM for which you want 64-bit support; software virtualization is not supported for 64-bit VMs"
I am guessing since virtualbox is software, it will not support a 64-bit OS running from a 64-bit OS VM. That is my theory, maybe post system specs and what exactly is happening when you go to create another VM inside your VM.
Let me get this straight. You have a host PC running VB. You then run 64bit Debian as a virtual machine. You then try to run a Windows VM inside the Debian VM?
Well, @Snickerz is right, you need VM processor and BIOS support to run a 64bit VM, the Debian VM doesn't give you that. I suspect that the VB developers never thought it would be needed :)