I'm newbie to ubuntu and trying to install ubuntu 16.04 into Windows 8 pre-installed desktop PC.
But it seems that something went wrong, and now I cannot boot neither Windows nor ubuntu, and only I can see now is UEFI window.
Followings are what I did so far.
[Ubuntu installation]
I created new partition in my HDD, and disabled fast startup via control panel in Windows.
I installed ubuntu 16.04 via image file in DVD. I chose "try ubuntu without installing" option, and then use "installing ubuntu alongside Windows boot manager" option in GUI installer.
Installation successfully ended, and I rebooted ubuntu.
[First boot problem]
After installing ubuntu, I shutdown ubuntu and boot Windows to check nothing went wrong.
1.1 At this time, grub normally started, and I could choose OS to be booted (Windows or ubuntu).
However, once I shutdown Windows, grub no longer appeared again. And every time I turned on PC, Windows automatically started to boot.
[Second fatal boot problem]
I followed this thread (Grub not showing on startup for Windows 8.1 Ubuntu 13.10 Dual boot) to solve this problem.
1.1. I tried following command. But nothing had changed.
bcdedit /set {bootmgr} path \EFI\ubuntu\grubx64.efi bcdedit /set {bootmgr} path \EFI\ubuntu\shimx64.efi bcdedit /set {bootmgr} path \EFI\ubuntu\shim.efi
I googled again, and found that sometimes Fast Boot is not properly disabled via control panel in Windows.
2.1. I opened UEFI menu, and noticed that Fast Boot option was still enabled.
2.2 I disabled Fast Boot, and (maybe carelessly) disabled Secure Boot option too.
After that, Windows no longer automatically booted, and UEFI option menu automatically opened every time I turned on PC.
3.1. Further, there was only Windows Boot Manager in the list of Boot Option Priorites (there used to be other options such as DVD disk driver).
I loaded UEFI defaults, but problem still unsolved.
I noticed that CSM option was also disabled, and I enabled it.
5.1. Then missing other options appeared again in the list of Boot Option Priorities.
5.2. However, UEFI option menu stopped to automatically open, and window shows
Reboot and Select proper Boot device or Insert Boot Media in selected Boot device and press a key
Is there any way to fix it?
NOTES:
I can still boot from ubuntu installation DVD.
My UEFI option menu is "Asrock UEFI Setup Utility"