Cfrgtkky

Please, how can I run 64-bit guests on a 32-bit host?

I have Oracle VM Virtualbox 4.3.12.
When I choose:

I can only find 32-bit. My host CPU is Intel(R) Core(TM)2 Duo CPU T6600 @ 2.20GHz.

from cat /proc/cpuinfo processor:

flags : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 constant_tsc pni monitor ssse3 bogomips

Your CPU does not provide VT-x harware virtualization needed for running a 64-bit guest OS in a 32-bit host. There is nothing we can do to overcome this.

In order to still be able to run a 64-bit application (as was said in a comment) let me suggest you run Ubuntu 64-bit either by a dual-boot, or as a live system from USB. A live system in persistence mode allows to save files in a reserved area.

Alternatively it is also possible to completely install a bootable Ubuntu on a USB drive/key:

• How do I install Ubuntu to a USB key? (without using Startup Disk Creator)

Support for 64bit guests requires CPU virtualization support in the host, A.K.A. VT-x (or AMD-v). You need to verify that your CPU has this feature .

Navigate to BIOS and enable it if its supported by your CPU , try to google your CPU Specs.

Conditions for running 64-bit guests on 32-bit hosts:

VirtualBox supports 64-bit guest operating systems, even on 32-bit
host operating systems, provided that the following conditions are
met:

• You need a 64-bit processor with hardware virtualization support (see Section 10.3, “Hardware vs. software virtualization”).




• 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.




• If you want to use 64-bit guest support on a 32-bit host operating system, you must also select a 64-bit operating system for the
  particular VM. Since supporting 64 bits on 32-bit hosts incurs
  additional overhead, VirtualBox only enables this support upon
  explicit request.




• On 64-bit hosts (which typically come with hardware virtualization support), 64-bit guest operating systems are always supported
  regardless of settings, so you can simply install a 64-bit operating
  system in the guest.



• 
  

  Warning

  
  
  

  On any host, you should enable the I/O APIC for virtual machines
  that you intend to use in 64-bit mode. This is especially true for
  64-bit Windows VMs. See Section 3.3.2, “"Advanced" tab”. In addition,
  for 64-bit Windows guests, you should make sure that the VM uses the
  Intel networking device, since there is no 64-bit driver support for
  the AMD PCNet card; see Section 6.1, “Virtual networking hardware”.