Posts Tagged ‘disable secure boot’

How to Fix Secure Boot Violation on UEFI-Based Computer

September 27th, 2019 by Admin

When your computer boots from a Live CD or a installation disk, you may get a red square in the center of a black screen, with the following error message:

“Secure Boot Violation. Invalid signature detected. Check Secure Boot Policy in Setup”

Secure Boot is a feature included on UEFI-based computers, which ensure that only Microsoft-authorized software can be booted. If you try to boot from a trusted but “unauthorized” operating system, you’ll still receive the “Secure Boot Violation” error. To fix this issue, you have to temporarily disable Secure Boot in the UEFI BIOS firmware.

How to Fix Secure Boot Violation on UEFI-Based Computer

  1. When turning on your computer, quickly and repeatedly press a certain key (F2, DEL, F12, ESC, etc.) to enter into UEFI BIOS.
  2. Navigate to the Boot (or Security) tab, select the Secure Boot option and set it to disabled. If the Secure Boot option is greyed out, you may need to enable legacy / CSM support first.

    For ASUS computer’s UEFI BIOS, you have to press F7 to enter Advanced Mode. Go to Boot -> Secure Boot, change OS type from “Windows UEFI mode” to “Other OS”. Secure Boot is enabled when the OS type is set to “Windows UEFI mode” and disabled when it’s set to “Other OS”.

  3. Press F10 to Save the changes and reboot. Your computer should boot up as it is supposed to, without displaying the “Secure Boot Violation” error message.

Fix Boot Failure: a proper digital signature was not found

August 10th, 2015 by Admin

I have a Toshiba P850/02c with windows 8. This morning it did an automatic Windows configure update but then on restarting, I got the error message “Boot Failure: a proper digital signature was not found. One of the files on the select boot device was rejected by the Secure Boot feature.” and stuck on there. Now I am unable to boot to the desktop. How can I fix the issues?


This is probably due to the “Secure Boot” feature currently on all new Windows 8/8.1/10 computers. Secure Boot is a new feature that improves the security of Windows. To fix this boot failure, you have to disable the Secure Boot option in the UEFI firmware.

How to Disable Secure Boot?

To disable the Secure Boot option, you have to access to the UEFI setup.

In UEFI setup, try to find a menu labeled “Security” or “Security Settings.” Once you navigate to it, head straight down to “Secure Boot”. There’s a possibility that you might have a “Secure Boot” option immediately when you arrive at the security menu, so look out for that also. Once you see a “Secure Boot” option, disable it. Then reboot the PC to check if that fix the issue.