After a forced Windows update, my computer now stops during startup with the message: "SECURE BOOT VIOLATION — Invalid signature detected, check Secure Boot Policy in Setup." I've tried restarting so I can press F2 and enter the firmware setup, but neither my keyboard nor mouse responds at that stage. I also tried a keyboard connected to a USB 2.0 port. What could have caused this, and how can I regain access to the firmware settings or repair the Secure Boot configuration?
3 Answers
If you still cannot enter setup, clear the motherboard’s CMOS using the manufacturer’s documented procedure. This normally restores firmware settings to defaults and may let you access the setup screen again, though it can reset boot order, memory settings, and other custom options. Before changing anything, check the motherboard or computer manual for the correct procedure. If the error remains afterward, the next steps are usually a BIOS update or contacting the manufacturer for compatible Secure Boot keys.
Since the keyboard and mouse aren’t responding before Windows starts, try a very basic wired USB keyboard in a different port—preferably a rear USB 2.0 port directly on the motherboard. Avoid hubs, wireless devices, front-panel ports, and gaming keyboards while troubleshooting. If that still fails, disconnect the PC from power, remove unnecessary USB devices, and perform a full power drain before trying the firmware setup again.
The update may have changed or refreshed the Secure Boot keys, or it may have exposed an outdated key or firmware compatibility problem. If you can reach the firmware settings, look for an option such as “Load Default Secure Boot Keys,” “Restore Factory Keys,” or a similar Secure Boot reset option. You may also need to update the computer’s BIOS or firmware if the manufacturer has released a fix.
I already tested the rear USB 2.0 ports, but I’ll try with only a simple wired keyboard connected and remove the other USB devices.