Can't run Windows 8 on VirtualBox if host proc does not support VTx/AMD-v proc

Can't run Windows 8 virtual machine using VirtualBox (4.2.4) on Dell 610 machine :(

Error message says:

VT-x/AMD-V hardware acceleration is not available on your system. Certain guests (e.g. OS/2 and QN) require this feature and will fail to boot without it

Looks like Win8 needs VT-x/AMD-V hardware to work.

Reference(s):
https://forums.virtualbox.org/viewtopic.php?f=2&t=48256