Windows 10: Using Alternate Boot Options: Boot from EFI Flash Drive does not work anymore

I have from the past 12 -13 years have always been able to create Linux boot disk to evaluate various Linux products and perhaps install or not.That does not seem to be possible anymore with the new menu options provided using Shift + Restart. It always gives ne an error cannot verify image.I have verified the ISO's Hash files and they match,I have used UUI, Yumi, Unetbootin, and Rufus,I do not want to DD the flash drive as sometimes it is really Destroyed and I have to toss a perfectly good flash drive, but that may be the Last Resort.Why am doing this? I used to evaluate for various clie

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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.

 

Win 10 booting from DVD or Flash drive

I have upgraded a Lenovo G40-70 from 8 to 8.1 to 10. All is well except I am unable to set either a DVD or Flash drive as the first boot option. I have tried every suggestion on the internet, upgraded my BIOS and nothing works. It always boots from the boot
manager.

The bios says the flash drive is activated, but it still will not boot from the flash drive.

 

Which tool to recover the EFI partition? Booted into Rescue Disk

There are some options:
clean install
custom install
remove windows updates as a trial and error step
repeat steps: recreate EFI partition, chkdsk and bootrec commands
Use Kyhi boot rescue and collect files for troubleshooting

In order to make a windows 10 iso you will need an 8 GB or larger flash drive.