Chipset for Virtualization Support

I've go a HP DC7800C with an Intel Core Duo 2 CPU upon which I want to run Hyper-V. The chip obviously supports virtualization, but the proper virtualization setting does not appear in the BIOS. HP has a "P" version of this machine which will run Hyper-V adn they clain the the required virtualization support is due to a different motherboard between the "C" and "P" models. Are they telling me the truth, that a different chipset is required for virtualaztion support, or should an mob that supports this CPU be able to support virtualization with as long as the BIOS supports it.