After 19.10 upgrade can't dual boot windows 10

[Royce]

Hi,
I just upgrade from Kubuntu 19.04 to 19.10 upgrade went smoothly and everything seem to work.
But on trying to boot to windows 10 through the grub menu it immediately returns back to the menu. No errors show up.
No problem booting to windows 10 directly via bios . Tried reinstalling grub but that didn't work.
Grub seems to be booting up in UEFI mode so it hasn't switched to old Bios way.
Downloaded "Super Grub2 Disk" and booted off USB and it had no problem detecting Linux & Windows. Also had no problem booting
into windows.

Any one have any idea's of what to check for next

Royce

[Qqmike]

Without performing your own surgery, for now, two quick options:

Use Boot-Repair to diagnose it, including a report it generates:
https://help.ubuntu.com/community/Boot-Repair

And a boot manager for UEFI is rEFInd by Rod Smith, available through your Muon package manager in Kubuntu:
www.rodsbooks.com/refind/

[roadrunner58]

I Have the same exact problem on my Acer laptop. I found that I am able to boot in to Windows by key F12 boot menu.

[Royce]

Will tried Boot-Repair but it didn't fix grub. It does give a very detailed log of your all your boot info. Reading through it I couldn't see any indications of a problem but I could have missed some thing.
Downloaded and installed rEFInd. That works with no problems, boot both kubuntu & windows 10. You can even get it to load grub, but grub won't load Windows. rEFInd fixes the problem but it would
be nice to know what grub is doing.

[Qqmike]

When you re-install GRUB, you boot into Kubuntu and do
sudo grub-install
and then do
sudo update-grub
to generate a new menu? (grub-install should also generate a new GRUB boot menu for you, but just for the heck of it, doesn't hurt to run the second command.)

Sounds like you are familiar and confortable using UEFI booting, and your PC is new enough to have it (>2011 or so). When you installed Kubuntu 19.10, you did it by making a bootable USB Kubuntu? And if so, when you booted your PC to install Kubuntu 19.10 (with the USB), did you boot the PC in UEFI mode? (That is, you boot the PC using the Kubuntu USB, you enter UEFI-BIOS firmware menus (in your PC), you identify the proper USB in the Boot list (which is the USB having some UEFI or EFI descriptor in its name, as opposed to just a Legacy USB boot))?

[Don B. Cilly]

And what is the output of
sudo update-grub
?

[roadrunner58]

And what is the output of
sudo update-grub
?

magnum@laptop:~$ sudo update-grub
[sudo] password for magnum:
Sourcing file `/etc/default/grub'
Sourcing file `/etc/default/grub.d/init-select.cfg'
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-5.3.0-19-generic
Found initrd image: /boot/initrd.img-5.3.0-19-generic
Found linux image: /boot/vmlinuz-5.3.0-18-generic
Found initrd image: /boot/initrd.img-5.3.0-18-generic
Found Windows Boot Manager on /dev/sda2@/efi/Microsoft/Boot/bootmgfw.efi
Adding boot menu entry for EFI firmware configuration
done
magnum@laptop:~$