How to enable the Intel VT virtualisation feature on a supported HP Proliant server running ESX 3.5 so that 64-bit guest VM’s can run

When you try to create or import a 64-bit host VM in your Virtual Infrastructure you may receive an error in the VI client along the lines of

Attempting to load an x64 operating system, however this CPU is not compatible with x64 mode

If you have a HP Proliant server that has processors that are 64-bit compatible then it is likely that you just need to enable the Intel VT feature in the BIOS.

To enable the Intel VT feature in the BIOS

Restart the HP Proliant server and press F9


Select ‘Advanced Options’


Select ‘Processor Options’


Select ‘Intel Virtualization Technology’


Select ‘Enabled’ and press the enter key to enable Intel VT


Press the Esc key to exit and then press the F10 key to save the configurations when prompted. The server automatically restarts but I also powered down the server to ensure a cold boot to confirm that the Intel VT option was correctly detected by ESX.