[GTALUG] war story: upgrading Win8.1 to Win10 on a triple-boot system

[D. Hugh Redelmeier]

If you wish to ever have a free-as-in-beer Windows 10 upgrade, you
have to do it before July 29th (according to my unreliable memory).
Windows 10 is OK except for the continuous leakage of information to
Microsoft.  But even earlier Windows versions are being updated to spy
too.  The main advantage of Win10 over its predecessors is that it
will be supported longer.  A second advantage is that your license is
recorded in the cloud so in future you can wipe Win10 and install it
again without much difficulty.

Windows 7 and on continually bombard you with update offers.  Some
even appear to be opt-out.  Don't accept these offers.  Download Win
10 once to a USB stick and install from there instead.  That means
that you will only have to download it once, even if the installation
fails a few times or if you have several machines.

To create a USB stick with the Win10 update, you need to use the
"Media Creation Tool", an option wherever you can download Win 10.
You can create a USB stick for64-bit, 32-bit, or both.  Then it is
just a matter of mounting the stick on the Windows non-10 system and
running "setup".

I've done this on several machines previously and it mostly worked (a
previous war story described puzzling disk space issues).

On my notebook, I attempted to upgrade 64-bit Windows 8.1 to Windows
10 from within Windows 8.1 using Win10 update from a USB stick.
Salient points about this notebook:
- partitioning / booting is MBR, not GPT / UEFI
- all OSs are 64-bit
- came with Win 7
- upgraded to Win 8 (free) and then Win 8.1 (free)
  (Thankfully I made recovery disks!)
- it has Ubuntu and Fedora installed
- booting is via Ubuntu's GRUB

It did not work.  The update process chugged for a while and then came
up with this helpful message

	Something happened.
	We can't tell if your PC has enough space to continue
	installing windows 10

Isn't that a great message!  It doesn't say why it cannot tell if
there is enough space.  It won't let me tell it (yes, it does have
enough space).  It just gives up.

If you google for this message, you will find lots of random advice on
this one.  Probably because there are a lot of causes.  I tried a few
of the easier ones with no success.  So I decided that perhaps Windows
needed to own the boot record.

I booted into the recovery system provided by the manufacturer.  I
pushed a couple of options (repair boot?  I don't remember and there
isn't a trace left).  The result was an unbootable system grub only
found enough of itself to report that there was a problem: none of its
modules were found.  I could not boot Windows, the Windows recovery
partition, or either Linux.

I then studied <https://peter.upfold.org.uk/blog/2013/02/28/restore-windows-8-bootloader/>.
I booted a Win 8 recovery DVD that I'd made.

- I tried "repair your computer" "advanced options" "Automatic Repair".
  Didn't work.  Apparently it put diagnostics in C:\Windows\...
  but there was no such filesystem.

- I tried "repair your computer" "advanced options" "Command Prompt".

  Set the "active partition" (as per first comment in that blog entry):
  > diskpart
	> list disk
	> select disk #
	> list partition
	> select partition #
	> active
	> exit

  > bootsect.exe /nt60 C:
  > BootRec.exe /FixMbr
  > BootRec.exe /FixBoot

  I don't really know what each step does, but it worked.  I could
  boot into (only) Windows 8.1)

>From Win 8.1, I clicked on "setup" from the mounted USB stick.  All
went uneventfully.

Now I will install Fedora 24 (replacing Fedor 20) and in the process
re-install grub.