How to enable Intel hardware virtualization on an HP xw4600:
* Boot into the hardware BIOS setup
* Got to Security -> System Security
* Enable both types of virtualization (VTx and VTd)
* Save settings, and power-cycle the machine.
I’m running Linux, Fedora 9, and using KVM, so I run the following:
modprobe kvm-intel
Loading that module will fail if hardware virtualization isn’t enabled.