How Do You Boot to One of Two Hard Drives?

Problem scenario
You have two hard drives in your laptop. You want to be able to boot to one or the other. The BIOS options are confusing. What do you do?

Possible Solution (directions primarily for HP laptops)

1. Power off the laptop.
2. Turn on the laptop and press "Esc" for the Start Menu.
3. Go to F10 BIOS Setup.
4. Go to the "Security" tab.
5. Go to the Boot Options -> Boot Mode. Choose either Legacy or "UEFI Native (without CSM)". If you alternate between these you may be able to boot to the hard drive of your choice.
6. In the Advanced tab, go to Multiboot Express Popup Delay (sec) -> Choose 5 sec (or longer).
7. Save all the changes. Each time you switch between them, you may have to go into this Startup Menu and the Security Tab and perform step #5 again. We know this is not an optimal solution, but it may or may not help you.