virtualbox.org

I've used virtual box seamlessly on my 32bit machine for sometime now. However, now that i've moved over to a 64bit machine so that that i can run MS Exchange along with my existing GNS3 network environment im having some trouble. I have tried to install various Windows OS like: XP, 7, and 8.1 and they all give some sort of error about attempting to install a 64 bit OS on a 32 Bit machine. I get this message form VirtualBox every time right after clicking start on the virtual machine.

VT-x/AMD-V hardware acceleration has been enabled, but is not operational. Your 64-bit guest will fail to detect a 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.

After reading a few topics on this exact issue i've update the bios on my Dell Precision T7500 and enabled the enable the VT for Direct I/O option. After enabling that option i restarted the computer and then turned it back off unplugging the power for about five minutes. I using virtual box 4.2.18 and i've also attached a virtual box log and a screen shot of my processor details. Any help is appreciated.

The "VT for Direct I/O" option is not the correct option, that's called VT-d. VT-x will be labelled as "Virtualization Technology" or similar in the BIOS, and may be in a separate security menu.

Also make sure you don't have Hyper-v starting up on host boot, or indeed running at all at the times you want to use VirtualBox.