Windows 10: windows 10 dualboot randomly disappeared in boot manager

Hi! I installed two windows 10 on two drives and the one is windows 10 standard and two is windows 10 with reviOS for fps boost and ReviOS is a Customized version of Windows and first I tried installing clean windows 10 to two drive and update all drivers then install reviOS using playbook and installed Fortnite i get 300-380 fps with reviOS and without reviOS i get 240-290 fps so reviOS is very good and after one day i tried boot into windows 10 standard and I realized that i did used some tweaks that removes hibernate and some so I tried enabling hibernate and update Armoury crate and after

:)

 

New Dell Computer and can't dualboot.  

@Tekkie Boy, I'm not mad at anybody. I really appreciate all the help! I ran mbr2gpt and am now having a different problem. @SIW2 mbr2gpt ran successfully. I restarted the computer, went into BIOS, changed boot order as below, then restarted computer again. The system tried to boot from my old SSD, but failed. The error is below (INACCESIBLE_BOOT_DEVICE). What do I need to do to the SSD out of my old computer so the installed OS (Windows 10 Pro) will boot on this new computer? BIOS now shows my SSD as boot option -- top of list (yea, first step).

Boo, Windows will not boot from my SSD.

This is how Disk Management showed my disk BEFORE mbr2gpt conversion (Disk 1).

This is how Disk Management showed my disk AFTER mbr2gpt conversion (Disk 1).

 

Dual Boot Windows question.

Knoxx29

EasyBCD will fix your dualboot on the fly. I've went forth and back several times with my dualboot.
Only thing I don't get working is the boot select screen to be from windows 10. It keeps showing the old and simple windows 7 boot select screen after a soft reboot.
But it works and that's what matters after all.

 

dualboot

So you installed Windows 11 since your original post or what, since you originally said your couldn't dual boot?