bios - LiveUSB of linux distros won't boot

So I have two laptops one from Acer,running Lubuntu and another from HP running preinstalled Windows 10.The first one uses Insyde BIOS and the second uses Aptio,American Megatrends.

The Acer one can boot almost all live usbs created using SliTaz,Puppy Linux,Tiny Core Linux,Damn Small iso etc., if I disable secure boot and change from UEFI to legacy.

But the HP laptop cannot boot into any except Puppy Linux. using that same USB. I tried disabling secure boot,changed boot order,change from UEFI to Legacy,but none works,it boots straight into Windows 10 everytime.These are the only options that I can change in the Aptio BIOS.

I confirmed that the USB drive loads beacuse on pressing Esc key before startup,I get a black options screen that has F9 to select boot device.If I press F9,the USB Drive is listed there.

Both can boot major distros like Ubuntu,Lubuntu,Debian etc.

What could be the probable cause for this and how can I make the HP Laptop boot the required USB?

Answer

Apparently the Aptio BIOS assigns platform keys to secure boot while the Insyde does not.I managed to boot the desired LiveUSB following these steps:

1. Plug in the USB.


2. Press Esc key until the start up menu appears


3. F10 to go to BIOS


4. Move to System Configuration>Boot Options


5. The default mode should be UEFI.



6. Disable Secure Boot.


7. The "Clear Platform Keys" should be highlighted now.Clear it.


8. Now change to Legacy mode.


9. Change the boot order for the Legacy mode.


10. Save and restart.


11. Repeat Step 2.


12. Now F9 for boot device options.If the USB is plugged in it should be displayed there.Select and press enter.

The LiveUSB boots.

If needed to re-enable secure boot:Change to UEFI>Enable Secure Boot>Load HP Default Platform Keys>Save and restart.