Verifying shim SBAT data failed:

Not being rude but to those saying to change something inside windows, idk about 10, but the message comes up on boot on 11 then shuts down you never even see an attemt to post, , I was dual booting, removed Linux, it's been working fine like that for years, but my bios has always shown my hdd as Ubuntu, even though its been running windows all this time, I believe Bitdefender total security is messing up, I had the pay version for years, soon as I didn't renew, it now grabs any files its doesn't like and deletes them, even when I know it's legit, I attempted to remove it, it would not kill processes for Bitdefender, and when I rebooted to attempt safe mode, all I get it that message, 2tb of games and all, and I'm gona attempt a few more things, I'll let y'all know how it goes, I used to be a computer tech, buuuut I didn't know Microsoft would decide to kill my windows.......😥

How to do this if I can’t enter to the pc?

This does not work for me. I have a dual boot windows 11 and. Ubuntu machine.

Hi, I am Dave, I will help you with this.

Are you dual booting Windows with Linux?

If you are, this is caused by a reported problem in the August update if you can get into Windows, either uninstall the August update, or open Command Prompt as administrator and run this command, then press Enter.

reg add HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecureBoot\SBAT /v OptOut /d 1 /t REG_DWORD

Then close Command Prompt

Tried this but didn't solve the problem. I was trying to boot into elementaryOS from my bootable USB.

I didn't find this solution in the responses so I post it here since it helped me:

https://learn.microsoft.com/en-us/windows/release-health/status-windows-11-23h2#3377msgdesc

Helpful videos:

https://youtu.be/YtA5JIEsbWo?feature=shared

How to enter Bios (solving the problem with the sudden shutdown) : https://youtu.be/lwaAIsNA59k?feature=shared