By default, all of the laptops we use here have secure boot enabled. Sometimes we need to boot from a USB for a few reasons. This is easy to accomplish by disabling secure boot and enabling legacy boot.
However, once we have completed what we need to do, and go back and re-enable secure boot and disable legacy boot, we can no longer boot as we get a message that states "Selected Boot Image Did Not Authenticate...." It is just a standard Windows 7 Enterprise OS, so not sure why it doesn't have the keys built in. Am I missing something simple here?