By default, HP ProBook 440G2 comes with Windows 7 Professional.
I need to change the boot sequence to boot from DVD drive:
1) Press F10 when you power on it.
2) click on Advanced
3) Scroll down to Boot Mode
Select UEFI Native (without CSM)
Scroll up to SecureBoot Configuration
Checked the box beside SecureBoot
4) Scroll down to UEFI Boot Order
Use + and – key to push Optical Disk Drive as first boot device.
This is also workable for HP ProBook 430G2 & 450G2.