14.04 Dual-Booted Well; New Install of 18.04 Breaks GRUB Boot Entry For Windows 8.1

[LillyDragon]

Hello! Recently upgraded to Kubuntu 18.04 on my ASUS desktop, and I'll say this upfront: I've never been happier to run a flavor of Ubuntu on it. Everything just worked out of the box, I only spent extra time setting up and installing my favorite open-source art programs, (All of which run faster than they do on Windows!) and my AMD APU's open-source driver now seems to perform 98% on par with its propriety Windows counterpart. If it weren't for one program I still need crashing on Wine, this would have been the year I ditched Windows on my main PC.

Only one thing really went wrong during the (very fast) installation process via a live USB made with Rufus. I don't think GRUB detected my Windows install correctly, while installing and configuring itself during the installation. Any attempts to boot to Windows 8.1 result in a black screen. (At least my monitor doesn't go to sleep for the lack of a signal, so this isn't too disastrous, right? :P ) I tried adding a custom boot entry in GRUB to see if I could fix this myself, but all I get is a short error message that kicks me back to GRUB.

I haven't seriously dove deep into GRUB's functionality since I needed to disable IRQ polling in Hardy Heron, to work around an APM power management bug that sent too little power to my Ethernet card, so in short, I'm a little stumped. (Hard to believe 8.04 wasn't yesterday!) Because of that, I have so little idea of what I'm doing, I don't even know what I should be looking up to help myself. :oops:

How I did the installation:



-Pointed the Kubuntu installer to my EFI partition on /sda2
-Wiped the ext4 partition I had Ubuntu 14.04 installed onto, and used that as the partition for the new OS
-Deleted the old swap partition and made a new one, just to be on the safe side
-Nervously triple checked the mount points of each partition relevant to installing Kubuntu
-Did not touch, format, or shrink the Windows partition
-Did not make a /usr partition separate from the OS's main partition
-Left SecureBoot alone and did not disable it, since I didn't need to disable it last time
-All boot entries on the GRUB menu look the same as before; even the working Kubuntu entry still says Ubuntu

Note: I don't know if it makes any real difference, but my 14.04 install was originally vanilla Ubuntu, then I installed KDE at a later point. This time, I installed a live USB of Kubuntu 18.04 instead


From what I have researched, it seems like installing Ubuntu alongside Windows 8.1 or Windows 10 only works flawlessly the first time around; performing a clean reinstall of a newer version of Ubuntu, in order to upgrade, sometimes results in a broken Windows boot entry. So, I'm not entirely alone on this one, but I suspect this is an edge case regardless.

Is there a way to fix my boot entry for Windows without letting the Boot Repair tool completely reinstall GRUB? I'm greatly concerned that would be overkill, if not run the risk of also breaking my Kubuntu boot entry.

[oldfred]

May be best to see details, use ppa version with your live installer or any working install, not older Boot-Repair ISO:
Just run the summary report, the auto fix sometimes can create more issues.
Boot Repair -Also handles LVM, GPT, separate /boot and UEFI dual boot, only use ppa download into Ubuntu live installer.
https://help.ubuntu.com/community/Boot-Repair
https://sourceforge.net/p/boot-repair/home/Home/

Note that grub only boots working Windows. Or if Window need chkdsk or is hibernated then grub will not boot it, but if UEFI install, you should still be able to boot from UEFI boot menu.
Windows updates also turn fast start up back on which is just hibernation. That then grub will not boot it, or any NTFS partitions will not mount read/write in Ubuntu.

[LillyDragon]

I disabled hybrid boot some time last year, yes, and haven't updated Windows 8.1 since I first turned on the system. (This later helped me avoid Microsoft's rounds of forced Windows 10 upgrades! My installation was too far behind on updates to get the memo. :p ) However, I wasn't aware that Windows Update can silently turn fast startup back on; I find this rather sneaky, thanks for letting me know.

As well, I have Boot-Repair installed from the latest version in the PPA on my Kubuntu installation. I can mount both of my NTFS partitions successfully and copy files from them, so I'm really hoping my installation of Windows isn't broken. As far as I can tell from Boot-Repair's summary report, as per your suggestion, neither partition has any errors.

However, this part of the log was concerning:



1 disks with OS, 2 OS : 1 Linux, 0 MacOS, 1 Windows, 0 unknown type OS.

Windows not detected by os-prober on sda4.


While it's otherwise not reporting any errors, and reading the names of partitions correctly, the os-prober couldn't find Windows on the partition where it's installed.

I noticed that in Boot-Repair's Advanced Options, it has an option labeled "Repair Windows boot files", which doesn't disappear when I de-select "Reinstall GRUB". Is the automated solution to repair only the Windows boot files a good idea, in this scenario, or could that potentially create more problems?

[oldfred]

Post link to summary report or re-run report and post that.

Boot-Repair does very little to fix Windows. Often turning on chkdsk flag which will make Windows run chkdsk on reboot which can take a long time. And if chkdsk flag is on, then the NTFS driver will not mount the NTFS partition until Windows is repaired with chkdsk.
It also can install a Windows type BIOS boot loader. But Microsoft copyrights prevent it from doing much more. For most Windows repairs you need a Windows repair flash drive which you can make from your Windows install (when it is working).

[LillyDragon]

So my hesitation to try that option was more justified than I realized. :oops: That sounds disastrous, thanks for the information.

Here is a link to the summary report:

https://www.dropbox.com/s/8br2vz44q013x5g/Boot-Info_20180915_1013.txt?dl=0

[oldfred]

You show UEFI Secure Boot on.
Grub will not boot Windows with Secure Boot on. Something about loss of signed trust.
You should be able to directly boot Windows from UEFI boot menu, often f8 or f12, should be same menu you use to boot flash drive.

[LillyDragon]

F8 is the key for that on my machine, and it worked like a treat! I didn't know the Windows boot loader is a boot option, just like running a live CD or flash drive; Windows booted like nothing had ever happened. (Save for the system clock being out-of-sync, but that sorts itself out once it syncs up with a timekeeping server.)

You saved the day for me, oldfred, thank you! I was legitimately laughing when I tried this.

Lightly tapping F8 on startup to boot Windows isn't too bad of a workaround, but if I wanted an even more convenient, permanent solution to this issue, what consequences would there be for disabling SecureBoot, so GRUB can load Windows directly?

[oldfred]

I do not currently use Secure Boot.
Historically there have been few boot virus. The main large scale one was actually by Sony in trying to control DRM's music.
If you have an operating system known to often get virus, what better marketing can you have than use Secure Boot. Even if most virus are not related to booting.

Torvalds clarifies Linux's Windows 8 Secure Boot position
http://www.zdnet.com/torvalds-clarifies-linuxs-windows-8-secure-boot-position-7000011918/
the whole UEFI thing is more about control than security

In the future we may want to enable it. And hopefully by then it works across multiple operating systems without lots of hassles.

[LillyDragon]

I'm mostly concerned about what technical issues might happen during the process of disabling Secure Boot, but this is also nice to know; sounds like SecureBoot has done little more than make dual-booting more complicated than it needed to be. I'll consider disabling it in the near-future, because VirtualBox refuses to build its kernel modules with it turned on, and it would be nice to boot to Windows from GRUB.

Thanks for all your help! :) I would still be at square one, or worse, without it. Marking this topic as solved.