Windows 10: Windows 10 Boot Manager no longer a Option in System BIOS

Good Morning Windows 10 Boot Manager: My system use to have a SSD 250 Drive as the C:\ Running out of disk space, I purchase a 2TB SSD drive to replace the current 250GB Drive. Trying to find a way to preserve the current data and Application already installed, I unplugged the 250-SSD from the system and Installed the new 2TB-SSD. I use my ORIGINAL Windows 10 64Bit software to do a new Windows 10 installation. After installation and all the upgrade from the installed version to the latest Edition Windows 10 Pro, Version21H1, Installed on ‎10/‎08/‎2020' OS build19043.985 Experience Windows Feature Experience Pack 120.2212.2020.0 : I shut the system down and put my old 250-SSD drive back into the system. When I then switch my PC on the following happened: a. The system did not boot, the message was "Please insert boot medium and hit enter to reboot." b. When the system reboot, I pressed the Del button to enter system BIOS setting. c. In the BIOS settings I could see my to SSD drives, selecting ANY of the two the original message appear when I exit the BIOS and restart "Please insert boot medium...." d. I restart the PC again and this time use F12 to access the One time Boot Menu. e. In the boot menu I could see my SSD drive and ONE BLANK OPTION. f. Selecting this one blank option my system restart and continue to boot as normal. Selecting any of the other SSD drives result in the same error "Insert boot medium..." Observation: 1 There is nothing wrong with my Windows 10 Pro setup because the system boot normally and work perfect. 2. The blank option manual selected does boot but cannot be booted as part of the system normal boot process. Even when it is set as the first boot option. 3. The system works normally except fot the fact that I have no Windows Boot Manager as a option in the BIOS and that I can only use the system and access the boot with the One Time Boot Menu. Please help me to get the system back to normal WITHOUT a complete re-install. The MAIN reason for not to re-install is that I have purchase and downloaded Windows Flight simulator 2020 and that took my 5 DAYS to download without the upgrades. I really do not want to go thru that process again. The must be some PowerShell option or simple command to re-enter the Windows Boot Manager in the BIOS or fix the current BOOT option. Could the initial small portion of the installation not be isolated to run only the part where this was originally created and available in the BOOT menu? Kind Regards Abrie

:)

 

No Windows Boot Manager on dual boot system (7 & 10)


I thought I'd just post a little guide.

This is the only thing that worked on my ASUS N55SF dual boot system: Win7 on HDD (MBR) and Win10 on SSD (GPT).

Step 1
Assuming that you have already Win7 installed on your primary disk, install Win10 on your secondary disk.

Step 2
When install is done, enter your BIOS and go to the Boot section. There you should see "Windows Boot Manager" as your default boot option. Change it so that your primary disk (where you have Win7 installed) becomes your default boot option (it should be something like "P0:" followed by your disk model number, mine is "P0: ST9750423AS"). Save and restart.

Step 3
Now Win7 should start automatically (no boot manager showing up). Enter Win7, open an elevated command prompt and run
bcdboot X:\windows
where X is the Win10 system partition as seen from Win7, typically E, F, G or H.

Step 4
Restart. You should now see the Windows Boot Manager (probably the Windows 10 GUI boot manager). Select Windows 10, install your audio drivers (if you already have, I suggest you uninstall them and restart before doing this), restart and you're done.

 

UEFI boot options disappeared from BIOS; now getting reboot and select proper boot device

In short, I need to get the system/BIOS to allow UEFI booting of the SSD.

Computer started up today with default BIOS settings.

• Only SSD 1(Windows boot) and SSD 2 were listed in BIOS; HDD 1 and HDD 2 were not visible
• System would not boot. Gave the 'reboot and select proper boot device' message
• Boot menu has no UEFI/EFI (or Windows Boot Manager) entries anymore

I went into Partition Magic/Gparted and confirmed :

• All drives are still showing
• All drives' data is in tact [EFI volume/partition is still listed (and can be browsed/files accessible)]

Gparted print out (note dev/sda2 apparently that is normal behavior) :

/dev/sda1 (locked) EFI System Partition--Fat32--/media/sda1--100.00mb--46.81MiB--53.19MiB--boot,esp
/dev/sda2 (exclamation mark) Microsoft reserved partition--unknown file system--no mount point--128.00MiB--unused spaced--msftres
/dev/sda3 basic data partition--ntfs--/media/sda3--118.58GiB--70.78GiB--47.80GiB--msftdata
/dev/sda4--ntfs--/media/sda4--450.00MiB--327.71MiB--122.29MiB--hidden,diag



As I am able to boot Windows installation from USB, I tried the standard startup repair. It said it was not able to fix any problems.

Next I tried to repair the EFI with Diskpart in the shell:

• sel vol 1 (note that Diskpart states EFI partition is 'hidden')
• assign letter=z:
• cd /d z:\EFI\Microsoft\Boot\
• bootrec /fixboot
• bcdboot c:\Windows /l en-us /s vz /f ALL

It completed all tasks successfully. Unfortunately that did not work.

Other things I have tried :

• Removing CMOS battery and replacing with a new one - my HDD started showing up again after doing this.
• Using the old MBR commands(in hopes it would force the Windows startup repair to recognize and fix a problem)

bootrec /fixmbr
bootrec /fixboot
bootrec /scanos
bootrec /rebuildbcd​

• Loaded BIOS 'optimized'/defaults (the system did this already once before, hence why I am in this situation, though doing it manually seemed like an option worth trying. Note that after doing this and restarting the system, HDD's stopped showing again)
• Removed new CMOS battery and left it out of the system for thirty minutes
• Formatted EFI and msftres partitions, then rebuilt the EFI boot records

In summary, am looking to force the BIOS to see the EFI partition on the SSD boot drive, as it is not an option any longer.

 

Windows stuck in automatic repair; Can't access BIOS/ boot menu

I've changed the boot order through both BIOS and the boot manager, as my original post stated. Neither did anything, but both were functional in the past. Neither listed the windows boot manager, either. Previously, it would boot just as expected whenever
other media was set as the first option, so I'm pretty sure there are no issues there.

As my original post suggested, I've already tried out the steps you gave. I've gone through all the options listed in the boot menu, UEFI or not.

My BIOS and boot menu settings were at their defaults when all of this started, so that's been tried already, if those are what you're referring to.