Windows Boot Manager; Dual Booting Windows 7/10 off different M.2 NVMe drives

Toggle sidebar Toggle sidebar
Tanyac

Tanyac

Reputable
Aug 30, 2014
745
8
5,415
For about the last year I've been dual booting Windows 7 and 10 whilst I try and make Windows 10 "safe and stable" for production use. Windows 7 booted from a Samsung 960 EVO 1tb drive and Windows 10 off a Samsung 960 EVO 250gb drive. Life was sweet. It worked perfectly, with both OSs disks showing up in the ASRock X99 Fatal1ty Professional gaming I7 BIOS as "Windows Boot Manager" (As opposed to Samsung xyz).

I used the Windows 7 Boot Manager on both OSs because Windows 10's Boot Manager does a restart and is much slower than the Windows 7 Boot Manager.

A few days ago I upgraded to an I9-7900x and an X299 Taichi.

And that's where the problem starts - I am damned if I know how Windows 7 came to show "Windows Boot Manager" in the BIOS. I cannot get it to do so now. I've tried several different images, trying MBR and UEFI boot options when creating the USB with Rufus 2.9. I even went so far as to boot from my Original Windows 7 DVD.

What are the requirements to get Windows 7 to boot from the Windows Boot Manager and not from the drive in the BIOS? (God I hope that makes sense).

I had a look at VisualBCD to manually add the Bootloader for Windows 7, but it's a little beyond my knowledge.

It is possible to get Windows 7 to show up as WIndows Boot Loader in BIOS and boot that way because I did it before... But if no one know how to do that, perhaps someone can guide me through manually setting up the boot manager to dual boot.

thanks
 
Sort by date Sort by votes
SkyNetRising

SkyNetRising

Titan
Jan 4, 2016
29,955
3,877
111,640
That option becomes available only, when booting OS installed in UEFI mode. It will not be available, if no OS is installed and you're booting from windows installation media.
 
Upvote 0 Downvote
Tanyac

Tanyac

Reputable
Aug 30, 2014
745
8
5,415


Uhuh. And from my original post "trying ... UEFI boot options when creating the USB with Rufus 2.9."

I'm not talking about pre-installation. I'm talking about post installation. Windows 7 is installed. In the BIOS is shows "Samsung 950 EVO 250gb" as the boot device.

I've also installing with CSM set to UEFI only for storage (in BIOS) with MBR for UEFI-CSM in rufus and GPT Partition scheme for UEFI.

 
Upvote 0 Downvote
SkyNetRising

SkyNetRising

Titan
Jan 4, 2016
29,955
3,877
111,640
Currently you have booted into UEFI mode from 1TB Samsung drive.
There should be Windows Boot Manager boot entry in BIOS boot priorities list.

But your system is also capable of legacy boot from 250GB Samsung drive. When multiple bootloader partitions are present in system, this might cause some level of confusion.

If you deleted System reserved partition from Disk 2, this would eliminate confusion with 2 bootloaders.
 
Upvote 0 Downvote
Tanyac

Tanyac

Reputable
Aug 30, 2014
745
8
5,415
Prior to the installation of my new I9-7900x and X299 motherboard I had a 1tb EVO and a 250GB EVO. The 1TB drive had Windows 7 on it. The 250gb had Windows 10. I've just reversed that around as I'm now using Windows 10 as my primary OS and Windows 7 for the multitude of programs that Windows 10 won't run.

Prior to the upgrade the BIOS boot menu showed Windows Boot Manager for BOTH drives. Selecting either as the primary boot drive resulted in the boot manager "menu" being shown at boot time from which I could select either OS.

Using MSConfig on either OS showed two OS entries.

The 250gb is now ONLY operating in legacy mode. Which is NOT what I want.

I want to replicate what I had before. I can't remember the combination of BIOS settings and/or image creation/boot mode/installation that I used to get that outcome. It's obviously possible because I did it once.

And as I said in the OP; If no one knows how to do this, then I would be happy to manually create a boot loader entry (Either with command line BCDEDIT commands or via VisualBCD or other Boot Loader editing tools) - with some guidance.
 
Upvote 0 Downvote
SkyNetRising

SkyNetRising

Titan
Jan 4, 2016
29,955
3,877
111,640
So - you want windows 7 to boot in UEFI mode, when booting from 250GB drive?
Yeah .. currently it is not possible.

UEFI mode can be booted into from GPT disks only. Your 250GB drive is partitioned in MBR.

You would have to:
  • create images of partitions from your 250GB drive (windows 7 partition matters there, others are one for bootloader and one empty);
    clean 250GB drive;
    initialize it to GPT;
    copy EFI system partition from 1TB drive to 250GB drive;
    restore windows 7 partition from image to 250GB drive;
    fix windows 7 bootloader entry on both drives (boot from windows 7 install media and use bcdboot command).
 
Upvote 0 Downvote
Tanyac

Tanyac

Reputable
Aug 30, 2014
745
8
5,415

Sorry for the late reply. The Tom's site no longer has the little green dot above my name to let me know when there are outstanding posts... And it's like out of sight our of mind and I'd forgotten about this post.

There is nothing on either system that can't be recovered or reinstalled. All data is on non-OS drives.

In any case, it wasn't that complicated when I first set it up. I had Windows 7 installed and running for several years. It showed "Windows Boot Manager" in the BIOS.

Then I installed Windows 10 in March 2017, and it showed "Windows Boot Manager" in BIOS.

I didn't reinstall Windows 7, just installed Windows 10 to a second M.2 SSD,

The steps I went through this time were similar to what you have listed (Except it's a clean install so no images were required)

Disconnect SATA drives
Clean 250g drive
Clean 1tb drive
convert both drives to GPT
Install Windows 7
Install Windows 10



Indeed! And therein is the problem..... My Windows 7 installation was GPT before I upgraded, now no matter what I do I can't replicate the same set up.

Anyway, for now, I can simply press F11 on reboot to get to Windows 7. I'll keep testing various things on my test-pc. Sooner or later I'm bound to replicate the same scenario and then I'll make sure I document it.

thanks for your assistance.
 
Upvote 0 Downvote
You must log in or register to reply here.

TRENDING THREADS

Latest posts

Moderators online

Share this page

COMPANY
RESOURCES
FOLLOW
Top Bottom