Greetings from a first time poster. I'm exploring the Linux word. As indicated in the title I'm running three OS versions. My HP laptop is a 15-bs244wm. I upgraded it to a 1TB SSD and up to 8GB RAM. I've reloaded Windows 10 before loading the two Linux versions. In Control panel - System - Advanced System Settings - Advanced - Start up and Recovery: Windows 10 is the only OS showing up. I suspect the HP BIOS is causing the issue. I can boot into Ubuntu and Mageia using the F9 key, but no Grub screen shows up at startup. I ran the efibootmgr to change the boot order without any success. I saw a post from Yara with a similar issue and tried the link suggested by Atanere. It completed successfully, but when I rebooted I still didn't get a Grub and the computer booted straight into Windows. I have legacy boot disabled and secure boot enabled in BIOS. Fedora is loaded somewhere (which could be my problem) but I can't find where on my SSD it's loaded so I can format that partition. I've been fighting this for many days. I hope you can help. Thank you. David