I have installed Debian on a Toshiba hard drive and Ubuntu on a Hitachi hard drive on a Fujitsu laptop. Now I'm trying to boot these two systems on a HP laptop, but neither will boot. After a few seconds of black screen, it boots into Windows in HP's hard drive. I've made sure that "USB Boot" is enabled and "Secure Boot" is disabled in HP's boot menu, and HP's hard drive is set to the end of the boot order. All three systems are 64-bit.
When I installed the two Linux systems I had only the corresponding hard drive and the installer USB stick attached to the Fujitsu laptop so I'm pretty sure the boot loaders are in the correct hard drive.
Is there any way I can boot the two Linux systems on both laptops?