I just tried using BootRepair, rather than just the update/reinstall of GRUB : The message about not being able to mount /dos is now gone when I go into Kubuntu and I am now able to get Windows10 up and running (it went through a lengthy recovery process to get there, but it is all good now). I suspect BootRepair took care of the UEFI issue. From what I understand, UEFI is the new Bios. Whatever....
Thanks for your help.
Last edited by woodburner; 10-09-2016 at 11:02 AM.
Reason: new information