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  • Kubuntu 14.04 64bit on a MS-DOS (MBR) type HDD (sda4)
  • Kubuntu 14.10 64bit on a GPT type HDD (sdb5)
  • Windows 8.1 64bit on a GPT type HDD (sda3)

these are my installed OSes, both kubuntu installations were made with "secure boot off" state. Now I need to turn secure boot ON. but enabling secure mode ignores the grub and head to windows 8. also it indicates an error with the boot saying "invalid signature detected..."

do I need to add grub-efi signature to efi-firmware? or how can I enable secure boot correctly?

motherboard intel DH77KC

Prasad RD
  • 2,013
  • secure boot and uefi are two different things, at least in my bios. These settings are enabled/disabled in your bios. As far as I know, with uefi, you need to install with uefi enabled (I do not know a way to convert post install). Generally you then select which OS to boot in your bios . Most of this is covered in http://askubuntu.com/questions/221835/installing-ubuntu-on-a-pre-installed-windows-8-64-bit-system-uefi-supported , see the troubleshooting section. – Panther Nov 30 '14 at 02:08
  • @bodhi.zazen thanks for your comment. yes secure boot and efi (or uefi) are two things (actually secure boot is a feature of efi which keeps windows secure) and I can also turn off secure boot and efi mode (secure boot depends on efi mode) in my bios. also it is possible to convert a regular linux installation to a efi capable installation :) – Prasad RD Nov 30 '14 at 14:01
  • there is no problem with efi-grub.... grub is installed as efi capable and system boots up with efi mode (CSM diasbled)...and I can use both kubuntu OSes and Windows 8.1 ...problem occurs when I trun on the secure boot option, I don't know where is the error...bios os the efi-grub...visual bios says signature error and it leads to windows straight without displaying the grub :( – Prasad RD Nov 30 '14 at 14:02
  • If it boots to windows without displaying grub, try looking at your bios and select which OS to boot from the bios. Most of this is covered in http://askubuntu.com/questions/221835/installing-ubuntu-on-a-pre-installed-windows-8-64-bit-system-uefi-supported , see the troubleshooting section. – Panther Nov 30 '14 at 15:02
  • From the link I gave you ..."TROUBLESHOOT

    YOUR COMPUTER BOOTS DIRECTLY TO WINDOWS

    This is a common problem and if you do not get a GRUB menu , re-installing or repairing grub will NOT HELP " read on ...

     – Panther Nov 30 '14 at 15:03

0 Answers0