I recently tried installing Ubuntu x64 in VMware on my 32-bit Windows machine. I have done this in the past for other 64-bit operating systems, however not on this particular workstation, which is an HP xw4600. The process is typically very straightforward since VMWare has a “Easy Install” process for known operating systems.

This time around I ran into some issues while the Ubuntu image was booting. Each time I tried to start the VM, I received the following error:

“This kernel requires an x86-64 CPU, but only detected an i686 CPU. Unable to boot – please use a kernel appropriate for your CPU.”

I was almost positive that my processor was 64-bit compatible, but I double-checked Intel’s site to make sure. According to Intel, I was gojod to go. I decided to give VMWare’s compatibility checker a try, and it stated that I was able to run 64-bit virtual machines as well.

I figured the issue was probably due to 64-bit extensions being disabled in the BIOS, so I took a look there. I dug and dug, but could not find any tabs or sections related to 64-bit extensions or virtualization. After looking around some more, I found my answer in a very unlikely location (at least in my opinion).

Under the main Security menu, there is an entry for System Security. There, you will find three values, two of which are disabled by default. These are Virtualization Technology (VTx) and Virtualization Technology Directed I/O (VTd). After enabling both of these items and saving my BIOS settings, I was good to go.

I applaud HP for being careful regarding Virtualization Technology, but they could have made the options or documentation regarding these options a little easier to find.