Symptoms
- Error text specifically mentions Secure Boot Violation
- Appears right after the BIOS logo, before Windows loads
- May follow a BIOS update, installing another OS, or a bootable USB left connected
- PC previously booted fine before this appeared
Likely causes
- CommonBoot loader or bootable USB not signed for Secure BootCertain Linux installers or older bootable tools aren't Secure Boot compatible by default.
- CommonBIOS/UEFI firmware update changed Secure Boot keys or settingsUpdates can occasionally reset or alter Secure Boot's trusted key database.
- PossibleMalware attempting to modify the boot processSecure Boot is specifically designed to catch and block this kind of tampering.
- PossibleDual-boot setup with a non-Secure-Boot-compliant OS installedInstalling certain other operating systems can trip this check.
- Less commonCorrupted UEFI firmware settingsRare firmware corruption can cause false violation detections.
What to do
- Remove any USB drives or discs and restart, since a non-compliant bootable USB is a very common trigger.
- If it persists, enter BIOS/UEFI setup and check the Secure Boot section for any pending key or policy update prompts.
- If you recently updated BIOS firmware, check the manufacturer's site for known Secure Boot issues with that specific firmware version.
- As a temporary test, you can disable Secure Boot in BIOS to confirm Windows boots normally without it, which confirms Secure Boot is the specific blocker.
- If disabling it works, re-enable Secure Boot afterward once the underlying cause (like a bad USB or dual-boot OS) is addressed, since leaving it off reduces security.
- If a dual-boot OS caused this, check that OS's documentation for Secure Boot compatible boot loader setup, such as using a signed shim.
- If you suspect malware rather than a hardware/software change, run a full antivirus/anti-malware scan from a bootable rescue disk before re-enabling Secure Boot.
Tools and parts
- Bootable antivirus rescue USB, if malware is suspected
When to call a pro
If you're not comfortable adjusting Secure Boot or firmware settings, or if malware tampering is suspected, a technician can safely diagnose and resolve this without weakening your PC's security.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.