I tried installing Ubuntu 16.04 LTS alongside the Windows 8.1 of my Vaio SVE15128CXS laptop. It is the first time I am trying to do this with an UEFI computer system, I read carefully the instructions to do it but I did not find Fastboot or quickboot in my UEFI system. Ubuntu is installed normally but my computer does not boot on Grub, I have to put in my usb key then boot into ubuntu, to restart my pc on ubuntu whenever i want to boot on Ubuntu, otherwise it directly boots on Windows. I tried to fix the problem with Boot-repair, but it did not work. And know I am asking you for help.
Please help me fix my problem ASAP, and thank you in advance.
Harpartap Singh
Your Boot Info output shows a very short list of bootable OSes, which includes neither Windows nor Ubuntu entries, both of which would normally be present on an installation like yours:
Chances are it's booting to Windows only because the computer is treating the Windows boot loader as a fallback boot loader in a way that does not show up in the
efibootmgr
output.Judging by dates of reviews of your model I found online, your computer seems to date from 2012, when many manufacturers shipped badly broken EFIs that had problems like this. The best solution, really, is to ditch the broken computer entirely; however, that's wasteful and may not be economically possible for you. Thus, you may need to look into a workaround, several of which are covered in my answer to this question:
efibootmanager -o changes are lost on reboot
I did notice that Sony's site includes a firmware ("BIOS") update from November of 2016, so I'd start by applying that and then trying Boot Repair again. In my experience, manufacturers seldom fix these truly egregious boot problems, but a firmware update four years after the product's release is also pretty extraordinary, so maybe Sony's actually done something about this problem.
my problem has been solved. As the Boot-info report suggested to do this:
=================== Suggested repair
The default repair of the Boot-Repair utility would reinstall the grub-efi-amd64-signed of sda8, using the following options: sda3/boot/efi, Additional repair would be performed: unhide-bootmenu-10s fix-windows-boot use-standard-efi-file restore-efi-backups
=================== Final advice in case of suggested repair
If your computer reboots directly into Windows, try to change the boot order in your BIOS. If your BIOS does not allow to change the boot order, change the default boot entry of the Windows bootloader. For example you can boot into Windows, then type the following command in an admin command prompt: bcdedit /set {bootmgr} path \EFI...\grub*.efi
So I did enter this line in command prompt on windows and problem was solved, my computer now starts on grub.
Thank you very much everyone for helping me solve the problem.