Bios bootloop when enabling secure boot, fix
https://www.reddit.com/r/ASRock/comments/1r42yiy/enabling_secure_boot_sends_me_back_to_bios/ https://www.reddit.com/r/ASRock/comments/1repdgv/asrock_secure_boot_and_windows/ https://www.reddit.com/r/ASRock/comments/1qwz53v/please_help_secure_boot_sends_me_to_infinite_boot/ https://www.reddit.com/r/ASRock/comments/1rc1705/b450m_pro4_stuck_in_bios_loop_after_enabling/
For anyone stuck in the BIOS infinite loop, I spent a few hours troubleshooting with Claude's help. When I recreated my boot file from my own system I didn't know it kept loading the 2011 boot keys but the latest bios in my b550m uses the UEFI 2023 key as of bios 3.90. I reflashed even back to the previous 3.62 bios and it still didnt work. That or a Windows update forces it to use the new key now, not sure.
The solution that worked for me was download a latest Windows.iso and make it using Rufus with the option to use UEFI 2023 keys. Then rename the bootx64.efi on the mounted ISO to bootmgfw.efi in recovery and copy it into your EFI/boot on your FAT partition. This got me out of the bootloop and now I can play BF6 again and I don't have to do a full system rebuild. Hope this helps.
Btw I emailed asrock support and they just referred me to their FAQ, guess it's time they get AI support...