Help with multiboot

#1
Hello,

I have a computer with 2 harddisks.
1. Windows 10
2. Linux (CentOS7)
I created both OS on seperate HDD.
When i want to boot in a different OS, i have to change the BIOS with the proper HDD as first boot device.
I tried with Easy BCD to create a boot menu to get the same result, but i am unable to get the thing working.
The Windows option works OK, but i can't get the Linux to boot.
Can somebody tell me if i am doing something wrong?

Henk
 

scot

New Member
#2
Hi Henkbart,

easybcd is a great answer. It will not install on Linux, but can certainly handle it. I am not a computer tech. but have
been helped here to multiboot several Windows systems and Linux

What I would do is
Install Windows 10 and Linux on separate HDDs with only one connected at a time, so each is self-contained.
Connect both HDDs, enter the BIOS and make the Windows 10 drive the first to boot.
In Windows 10, install easyBCD and add the Linux drive to it's Boot Menu via the "Add new entry" page - I chose the
"GRUB2" option and let easyBCD do the rest. In the "Edit boot menu" page, select Windows 10 as the default drive,
then click the "Save settings" button.
The next start-up should show the O/S selection window.

CAVEATS:-
1. easyBCD must be installed in the newest version of Windows that you have on your computer, because it will not
recognise later system versions than the one in which it is installed. Also, in easyBCD, make this the "Default System".
2. I find major Windows 10 updates can sabotage the arrangement and start Windows 10 exclusively. But, with
easyBCD being installed in Windows 10, it is simple to open easyBCD, confirm all the settings are still correct, then hit the
"Save Settings" button again. Upon restarting the computer, the easyBCD selection menu will be back to normal again.
3. easyBCD will install folders in a NST folder in Windows 10 Root, for additional systems. I think they contain the
actual starting data for systems selected. My Ubuntu folder is labelled "AutoNeoGrub3.mbr"

ADDITIONAL TIP:-
To quote Terry60's great reply to my plea for help (Multibooting Ubuntu with easyBCD);-
"Don't use "write MBR" when doing routine BCD tasks.
It's an advanced function for repairing broken-boot systems to which you still have access.
Just add entries and click the "add entry" button. That's it.
Writing the MBR undoes everything else you just did. "
 

Terry60

Knows where his towel is.
Staff member
#3
If your PC is UEFI, then it cannot be made to dual-boot with Linux through the MS bootmgr (even with the help of EasyBCD).
It's a MS prohibition.
You can let Linux take control of the boot and dual-boot Windows through grub.
 

scot

New Member
#4
Thankfully, my PCs still use BIOS.
I would really appreciate it if you explain how to "let Linux take control of the boot and dual-boot Windows through grub".
I might well do that, because Windows squeezed out other systems by UEFI, now other Search Providers and Browsers - what next?
 

Terry60

Knows where his towel is.
Staff member
#5
It's been many years since I ran Linux, but back then it was just about the first question the Linux install asked you. By default it would commandeer the boot, and the trick was not to just keep clicking "yes" to all the install screens if you didn't want it to do so, as shown in the following extract from
Linux
grub.JPG
Can't guarantee it's still the same after all this time, but the option will be in the install process somewhere.
 

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