I enabled Secure Boot in the UEFI settings because a security requirement told me to turn it on. Since then, my laptop says there is no boot device and keeps returning to the BIOS. I've tried disabling Secure Boot, saving the changes, and restarting, but it comes back enabled every time. I'm not sure whether Windows was installed in Legacy/CSM mode or using an MBR drive, and I'm not very familiar with these settings. How can I get the laptop booting again without losing my files?
1 Answer
Secure Boot generally requires Windows to be installed in UEFI mode on a GPT-formatted drive. If the laptop was originally set up using Legacy/CSM mode with an MBR drive, enabling Secure Boot can make the firmware unable to find Windows. In BIOS, look for Boot Mode, UEFI/Legacy, or CSM settings. Try restoring the previous mode—often disabling Secure Boot and re-enabling Legacy/CSM—then make sure Windows Boot Manager or the internal drive is first in the boot order. If the settings keep reverting, use the BIOS option to restore optimized/default settings, save, and reboot. Don’t reinstall or format anything until the installation mode and drive layout are confirmed.
I’m not sure what mode or partition type the laptop used before, since I didn’t check those settings. I’ll look for the UEFI/Legacy or CSM option and restore the original boot mode rather than changing anything else.