I have switched to Legacy Mode, disabled Fast Startup on Windows 10 before attempting installation of Fedora 23. The installation ran successfully, albeit with a network driver error unseen before, which gets fixed after replacing the original one with a newer driver.

Post-installation (at that time the kernel is 4.4.6) I have rebooted twice with UEFI and Secure Boot enabled to ensure the Windows 10 continue to run properly. Booting into another OS requires me to change the boot mode in BIOS - Legacy for Linux, UEFI for Windows. The grub menu cannot show Windows 10 in Legacy mode, and in UEFI mode my laptop automatically boot into Windows 10.

I left Windows untouched ever since. After updating the kernel to 4.4.7, I found that I cannot boot into Windows again. A "No bootable device" error pops up every time under UEFI, hence the Windows cannot be booted in any way, though my Fedora 23 continue to run smoothly under Legacy. I am using Acer Aspire V15 with GPT partition table. I wonder if a re-installation of Windows would work; my personal data (/home) is stored in a separate partition than the Fedora system (/) and Windows. Please help. Thank you.

Disk layout (sudo fdisk -l)

/dev/sda1 2048 1230847 1228800 600M Windows recovery environment

/dev/sda2 1230848 1234943 4096 2M BIOS boot

/dev/sda3 1845248 2107391 262144 128M Microsoft reserved

/dev/sda4 2107392 147736615 145629224 69.5G Microsoft basic data

/dev/sda5 147738624 466913279 319174656 152.2G Linux LVM

/dev/sda6 466913280 500117503 33204224 15.9G Windows recovery environment

  • Not sure what happened, but it may be worth considering not using UEFI/Secure Boot with Windows (if switching after install is possible), this related Q seems to say it's up to you superuser.com/questions/860941/… – Xen2050 May 4 '16 at 10:57
  • I'm just afraid of reinstalled Windows will become inactivated, hence I plan to migrate my Linux installation...I prefer UEFI for less GRUB problems though. – MarcoXerox May 14 '16 at 2:44

Mixing boot modes (BIOS/UEFI) is not a good idea.

Windows can boot only UEFI way from GPT disk.

Linux/Grub can boot BIOS and UEFI way from GPT disk.

What has happened during legacy installation of Linux (would be nice to have concrete info about your disk layout):

  1. For booting BIOS way from GPT disk a special partition is created which contains boot code for Linux.

  2. A so called mixed MBR is created in place of normal protective MBR on GPT disk. This mixed MBR contains initial boot code (in case of protective MBR there is no boot code in MBR)

For booting Windows on GPT 3 things are needed:

  1. Correct disk layout (correct GPT disk structure + EFI System and MS Reserved partitions)

  2. Windows EFI boot files on EFI System

  3. Correct BCD (again on EFI System)

Any GPT capable disk utility can be used for fixing 1.)

Use bcdboot command from Windows Recovery media to fix Windows EFI boot (point 2. and 3.)

Why not install Linux in UEFI mode ??? (maybe just reinstalling GRUB in UEFI mode would be enough (after fixing Windows boot) so you would have a proper dual boot over GRUB menu)

Ask if you need more help.

  • I suppose the kernel update breaks my EFI partition, which is very strange. I tried installing Fedora with Live USB beforehand, in UEFI mode, but eerily I cannot change the priorities of boot media, hence it always boots into Windows when not in Legacy BIOS. That's the reason I install Linux in BIOS mode. Thanks for the advice. – MarcoXerox May 14 '16 at 2:41
  • @MarcoXerox You need to change the boot order in your BIOS, so that the HDD is listed above Windows Boot Manager. – Michael Hampton May 16 '16 at 6:04

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