New
#1
can't boot Grub2 with Win10 BCD boot manager
For years, I've been able to switch back and forth between Ubuntu's Grub boot manager and Windows 7's boot manager on my laptop's SSD before actually selecting one or the other OS to boot. When I selected Windows on the Grub menu, the Win7 boot manager would present its menu which included Ubuntu. If I then selected Ubuntu, Grub would bring up its boot menu which included Windows. But now, with Win10, selecting Ubuntu from the Windows boot menu doesn't launch Ubuntu's Grub2, but instead results in a BIOS POST. (My laptop doesn't have UEFI.) With Grub, I am still able to select either to launch Ubuntu 18.04 or to launch Windows 10's boot manager, so I can thereby run either OS. The aesthetic objection is the asymetry, and the problem is almost certainly with Windows 10's BCD operation.
Running "bcdedit /v" in Win10's Powershell, the Ubuntu entry seen is:
Real-mode Boot Sector
---------------------
identifier {916e05e4-d073-11e8-a243-001e4ce02067}
device partition=C:
path \mbr.bin
description Ubuntu 18.04
where \mbr.bin is a copy of the SSD device MBR after Ubuntu was installed. It presumably is fine because as the 1st 512 bytes of the SSD, it gets control from the BIOS and causes Ubuntu's Grub2 boot manager to launch, from which I can select either Ubuntu or Windows. But for some reason, \mbr.bin doesn't seem to work. When I run "dir" on Powershell, it shows the attributes of \mbr.bin to be -a---- . Is that enough attribute to allow the system to run it? Or should I add some other file attribute(s) to allow it to run?
TimDaniels