To disable Secure Boot, power off the VM and then open the VM settings. Under Secure Boot, uncheck the box "Enable Secure Boot" and then click "OK". This will allow the VM to boot the "unauthorized" CD image.
To disable Secure Boot, power off the VM and then open the VM settings. Under Secure Boot, uncheck the box "Enable Secure Boot" and then click "OK". This will allow the VM to boot the "unauthorized" CD image.