1. Turn on the computer and go to the BIOS menu.
2. Make sure that Secure Boot is turned enable. It should be under the Boot tab or the Security tab.
3. Go to Security tab and look for “Select an UEFI file as trusted for executing” and click enter.
4. You should see your hard disk like HDD0 etc here. If you have more then one, choose the HDD where you install Ubuntu. Press Enter.
5. You should see . Press enter.
6. You’ll see in next screen. Press enter.
7. You’ll see shimx64.efi, grubx64.efi and MokManager.efi file here. The important one is shimx64.efi here. Select it and click enter.
8. In next screen, type Yes and click enter.
9. Once we have added it as trused EFI file to be executed, save and exit the BIOS menu, your computer shold now boot Ubuntu.