Upgrading to a new release using a virtual CD drive requires preparation. The virtual appliance boots from the hard drive, by default. When you want to upgrade or reinstall a virtual appliance using the virtual CD drive instead of the internal image, change the boot order.
After you bind the .iso image to the virtual machine, perform one of these tasks immediately after the virtual appliance is powered on so that booting from the CD drive takes precedence:
Press the Esc key to enter the BIOS boot device menu and select the ISO image.
Press the F2 key to enter the BIOS setup screen and place the CD-ROM Drive option above the Hard Drive option in the static boot order list.
By default, the virtual appliance does not wait for you to press the Esc or F2 key before booting from the hard drive. To delay the boot sequence in the virtual appliance:
Open the Edit Settings dialog box for the virtual machine.
Click the Options tab and select the Boot Options section.
Request a force entry into the BIOS setup screen by selecting Force BIOS setup, or add delay in milliseconds in Power on Boot Delay, within which you can press Esc or F2.
Click OK.