Background information.
My youngest's computer failed to boot recently so I went to look at it. Tried all the usual checks and culprits. In the end took it to an excellent local repair technician. It would appear a drop of sweat when I was putting it together (10 years ago) fell near the EC controller so nothing would boot and would need a microsoldering which he did not do.
So jumping forward a replacement motherboard was installed that was able to take the existing DDR4 modules.
Next the fun part. I had forgotten I had purchased an O.E.M. edition of Windows 7 Pro before it got updated to 10 then 11 on the failed motherboard. So this meant purchasing a new O.E.M. key (but not from MS).
Next up I installed LMDE 7, added Plasma and made it look like Windows 11. So as not to have the same experience with my machine where installing EndeavourOS wiped out my main drive instead of the one I pointed it to install at, I disconnected the SATA data cable from the Windows drive.
Now for the fun part. Ran
sudo update-grub
No pickup of Windows.
Then
sudo os-prober
Zilch.
Solution?
-
Installed rEFIned.
-
Edited the /etc/default/grub
sudo nano /etc/default/grub
Had to change the initial boot entry from
...="0"
to
...="WindowsBootManager"
then wrote out with Ctrl+ O then exited with Ctrl+ X. Then
sudo update-grub
to make it stick.
This makes Windows boot first, but not exactly. rEFIned solves the failure to enrol LMDE 7 MOK keys into the EFI section of the BIOS.
So their is an Option to change from booting into Windows and choose the icon in rEFIned to boot into LMDE 7.