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.
Acer Aspire V3-471G – After trying out Windows 10 Technical Preview, i wanted to installed Windows 7. But System doesn’t response to F2 key at boot for me to change the boot sequence (to boot to DVD drive).
Windows 8 and Windows 10 using UEFI instead of BIOS.
1) In Windows, click on Windows key and type advanced settings and press enter
2) Click on Restart now button at the Advanced startup
3) Click on Troubleshoot
4) Click on Advanced options
5) Click on Startup Settings
6) Click on Restart button
7) System reboot.
Now i am able to press F2 to access BIOS.
Above steps also workable for Windows 8.
What is UEFI? – http://windows.microsoft.com/en-US/windows-8/what-uefi