So, the yesterday I installed RemixOS. Pretty much an Android based OS. After that, I went into Control Panel, system and security, system, advanced system settings, and settings under the Startup and Recovery. I checked box Time to display list of operating system, restarted and it worked. Windows Boot Manager screen appeared. Today however, it didn't go so well. I tried to boot into RemixOS through the same method, using CMD, etc. and no luck. It just booted straight into Windows 10. Anyone know a solution to this? At least a way for me to enter the Windows Boot Manager screen again? PS: I installed RemixOS on a separate partition.