Two M.2 drives on Maximus XI Hero

[eziocin]

Hi,
I have recently built a new PC on a Maximus XI Hero. First set up was with just one M.2 Samsung EVO 970 installed on slot M 2.2. Everything went well and the system is up and running flawlessly.
Then I wanted to make another OS installation in order to have two systems on the same PC, and I installed a Sabrent Rocket M.2 on the slot M 2.1, but there is no way I can get an OS working on this second drive. I mean, I can install the OS using a USB drive, the install procedure identifies correctly the second M.2, and apparently the OS installation completes OK, but then it fails upon reboot.
What am I doing wrong here ?
Thanks for your help

Ezio

[ASUSBuff]

Can you tell us what OSes you are using?

[eziocin]

Can you tell us what OSes you are using?

Win 10 Home version 2004 latest build

[ASUSBuff]

Win 10 Home version 2004 latest build

Dual booted with the other OS? Or are you using Windows 10 as the other boot option?

[eziocin]

Dual booted with the other OS? Or are you using Windows 10 as the other boot option?

Dual boot with one Win 10 installed on the first M.2 and another Win 10 installed on the second M.2.
I have been using this configuration for years with SATA SSDs on my previous rig

[ASUSBuff]

I don't know if this will help you
https://techxero.com/2018/04/07/dual...parate-drives/

[eziocin]

I don't know if this will help you
https://techxero.com/2018/04/07/dual...parate-drives/

Thank you... it looks promising: I will test it tonight..
Ciao

[eziocin]

I don't know if this will help you
https://techxero.com/2018/04/07/dual...parate-drives/

I followed the procedure in the link. I managed to install Win 10 on the second M2 and was able to reboot. Installation completed successfully, then I installed the chipset driver, audio drivers, etc, but on the next reboot, when I selected that OS from the Windows Boot Manager, it failed with the same warning and error code I had received in my previous attempts...
Just made another test: using a normal SATA SSD drive connected to one of the SATA ports as a target for the additional Win10 installation rather than another M.2 , I can make a flawless OS installation and reboot with no errors as many times as I want.
The thing that puzzles me is that if there was an inherent problem with Boot Manager occurred during the second Win10 installation I should not be able to boot to that system anyway, while here I can boot once but no more than that.... I am confused
Any idea would be greatly appreciated
Thansk

Ezio

[eziocin]

I made another test. While still keeping the first M.2 connected, I plugged in a SATA SSD and installed Win10 on it from USB drive. Flawless installation as well as no reboot issues, Everything working fine, I could boot on both installations fron the Windows boot manager. Then I plugged in the second M.2 and cloned the SATA SSD on it. Unplugged the SATA SSD and rebooted. Boot ok on the first M.2, boot failed on the second M.2.
I have no more ideas how to fix this issue.

[eziocin]

I fixed the issue in the simplest way...shame on me for not thinking about it earlier: unplugged all drives including the first M.2, except the second M.2. Installed OS via USB on the second M.2 and then reconnected all other drives. Everything working flawlessly now.