Hi All

I've recently upgraded to the latest VirtualBox (3.1.4 r57640) and want to install Windows 2008 64bit. When I try and start the VM I get the error message:

"VT-x/AMD-V hardware acceleration has been enabled, but it is not operational. Your 64-bit guest will fail to detect 64-bit CPU and will not be able to boot.

Please ensure that you have enabled VT-x/AMD-V properly in the BIOS of your host computer."

My first thought was to disable VT-x/AMD-V for the VM just to get it going, but it gets turned on again automatically. So, of course I checked the BIOS as I was sure I had turned virtualisation on already, and yet I have and I can't see any further relevant settings.

My motherboard is a GA-MA770-DS3 (F6) and I have a Phenom Quad Core 9850 processor.Do I need to upgrade the BIOS to get this to work? If so, how to I find out which revision of the board I have? The ASUS site says there are three revisions.....

Any advice greatly appreciated...