Hello Samuel,
I wanted to follow up and see whether you were able to identify what changed before the "Secure Boot Violation - Invalid signature detected" message began appearing.
Were you able to verify:
- Whether the issue occurs when booting the installed Windows operating system or only when booting from external media?
- Whether any BIOS/UEFI update was recently applied?
- Whether restoring the default Secure Boot keys in the firmware changes the behavior?
Since you mentioned that you already performed the commonly recommended procedure and the violation still appears, I would be particularly interested in whether the firmware currently shows:
Secure Boot = Enabled
Boot Mode = UEFI
Legacy/CSM = Disabled
and whether the platform reports that the factory Secure Boot keys are installed.
If you can still access Windows, please also check:
Confirm-SecureBootUEFI
and:
msinfo32
and share the values shown for:
BIOS Mode
Secure Boot State
Those details will help determine whether we're dealing with:
- A Secure Boot key database issue,
- A firmware/BIOS configuration problem,
- Or a bootloader/signature validation issue.
Additionally, please let us know the manufacturer and model of the device, as Secure Boot options and recovery procedures can vary significantly between vendors.
Any update you can provide will help narrow down the root cause and determine the next troubleshooting steps.
I hope this answer has brought you useful information. If so, please click on Accept Answer and consider upvoting it. Doing so helps other community members identify useful solutions to similar issues.
Thanks,
Maurice