Windows 10: Safe mode unavailable after enabling secure boot

Hello,

I've installed Win10 without UEFI/secure boot (a classic MBR drive with NTFS), a few days ago I used mbr2gpt to convert the system drive to GPT and then enabled UEFI and Secure Boot by enrolling the EFI keys from bootx64.efi in my BIOS. From that point I've lost the ability to boot into safe mode, anytime I try that, it wrecks booting to the point where right after startup it goes into automatic repair and then fails, BCD and Winload missing. I have to repair the EFI hidden partition with diskpart and bcdboot from command prompt inside the recovery environment to be able to boot up normally again, thankfully no install media needed, the bootloader looks unaffected.

Anyone with an idea on what it's about and how to fix it would be welcome *Smile
Thanks

Dex

:)

 

Stuck in boot error loop: The operating system couldn't be loaded because a critical system driver is missing or contains errors.

There is no Startup Repair option, these are the options available:

1) Enable debugging

2) Enable boot logging

3) Enable low-resolution video

4) Enable Safe Mode

5) Enable Safe Mode with Networking

6) Enable Safe Mode with Command Prompt

7) Disable driver signature enforcement

8) Disable early launch anti-malware protection

9) Disable automatic restart after failure

Press Enter to return to your operating system.

 

regsvr32 error at startup

Hi William,

I suggest you to boot to safe mode and check if you are able to boot and sign in properly. If the operating system is able to boot successfully and allows you to log on to your computer with an administrator account, entering into Windows 10 Safe Mode should
be easy (and so would rectifying the issue). Boot the computer to Safe mode and check if it persists. Follow the steps given below to boot the computer in safe mode.

• Press Shift Key and then restart your computer,
  
• Windows 10 will reboot and ask you to select an option. Choose Troubleshoot.
• Then, on the Troubleshoot screen, select
  Advanced
  options.
• On the Advanced
  options screen, choose
  Startup
  Settings.
• Windows 10 notifies you that you can restart your device in order to change advanced boot options, including enabling
  Safe
  Mode. Press
  Restart.
• After Windows 10 reboots, you can choose which boot options you want enabled. To get into
  Safe
  Mode, you have three different options.
  
• To enable Safe
  Mode press the
  F4 key on your keyboard.

Let us know the status of the issue.

 

Just to confirm, booting in normal mode with secure boot enabled is perfectly fine and it's just safe mode that's problematic?

Can you try booting to safe mode with logging enabled to see how far it is getting? Enable or Disable Boot Log in Windows Windows 10 Tutorials

 

Hello, my boot log wasn't showing anything unusual. I was able to fix this myself however, the GPT conversion didn't preserve the BCD entries and ReagentC config needed to run safe mode properly, after following the instructions here:
https://www.winhelp.us/restore-windows-re.html

I was able to restore the OS as if it came cleanly installed.