Tag Archives: Dell optiplex 755

How to enable virtualization on a Dell Optiplex 755 to run Hyper-V

I have been building some test Windows 2008 Hyper-V server’s on Dell Optiplex 755 workstations with 8GB of RAM recently, and I thought I would let you know what settings to change in the BIOS to make this work.

At first I was getting some errors like these below:

  • Hyper-V launch failed; Either VMX not present or not enabled in BIOS.
  • Hyper-V launch failed; at least one of the processors in the system does not appear to provide a virtualization platform supported by Hyper-V.

This was happening because I had missed the Execute disable setting in the BIOS. To fix this, boot the computer and press F2 to enter the BIOS.

In the BIOS you need to change the following settings

  • Security > Execute Disable (set to On)
  • Performance > Virtualization (set to On)
  • Performance > VT for Direct I/O Access (set to On)
  • Performance > Trusted Execution (set to Off)

Save and exit the BIOS, then power the computer down. You must power it down for the settings to take affect.

You will now being able to run Hyper-V on your Dell workstation!