Windows 10 And Windows 11 On Same PC - Two Separate Drives

TLDR: Installed Windows 10 and 11 onto 2 separate SSD drives. Swap drives and only one drive will boot while the other one won't. Used same purchased Windows 7 key to activate both.


I am puzzled by this experiment with Windows 10 and Windows 11 on the same old custom built pc.
Both 10 and 11 clean installed on 2 separate SSD's (not VM) using a single purchased Windows 7 key.

Timeline...
#1 Clean Installed Windows 10 using Rufus boot USB with Windows 10 ISO on a SSD without internet until install completed. Activated using purchased Windows 7 key.
Checked activated Windows 10 key using app ShowKeyPlus which does not match purchased Windows 7 key and displays OEM key not present in firmware. Windows Build Version: 22H2 19045.2846 (64-bit OS)

Next...
#2 Clean Installed Windows 11 using Rufus boot USB with Windows 11 ISO on another ssd without internet until install completed. Activated using same purchased Windows 7 key.
Checked activated Windows 11 key using app ShowKeyPlus which does not match purchased Windows 7 key and displays OEM key not present in firmware. Windows Build Version: 22H2 I didn't record the number (64-bit OS)

Next...
I put Windows 10 SSD back into PC and power up. Windows 10 will not boot up. PC just shows a blinking cursor at the left top.
I repeat timeline #1 above again. Checked activated Windows 10 key with app ShowKeyPlus which still does not match purchased Windows 7 key or the key in #1 above.

Next...
I put the Windows 11 SSD back in the PC and power up. Windows 11 will not boot up. PC just shows a blinking cursor at the left top. Same results as Windows 10 above.

Next...
I put the Windows 10 SSD back in the PC and Windows 10 boots up normally.

What rule am I breaking here?
The internet wasn't active In all instances of swapping out the SSD's.
This is similar to having Windows 10 and Windows 11 running on a single physical SSD in a VM environment with 2 partitions. It's just 2 separate SSD's instead.

Apparently, The ShowKeyPlus app is showing me a digital license key for each install instead of the purchased Windows 7 key I used to activate with.

Sorry for the long post!

Megahertz said:

Did you detached (SATA or power cable) ALL other drives when doing the clean install?
If you didn't the OS can be in one drive and the OS on another.

Please post a whole window Disk Manager image of ALL your drives. Don't forget to expand the columns so we can read them. How to Post a Screenshot of Disk Management
If you have a MiniTool or AOMEI Partition use it instead or Windows disk manager.

Yes, I detached the SATA cables on all drives. I attached the Windows 11 SSD using a SATA to USB adapter so it will show up in disk manager.



I think BIOS is hiding something and he isn't talking!

Megahertz said:

ASRock Z68 Extreme3 Gen3 has a boot menu that you launch with a F11 key during POST so you can select a different drive to boot from.
It should show Win 10 and Win 11 boot manager as your system is UEFI-GPT.

I don't think you can boot from the drive on the USB adapter.

I have used F11 (Boot Menu) a many times. Boot menu only see possible boot devices connected to the motherboard along with Windows Boot Manager. It does see my Windows drive though.

The motherboard is UEFI only with legacy backward compatibility.
I didn't attempt to boot the Windows 11 drive from a USB port. I only plugged it in so it will show up in Disk Manager.

Here's Disk Manager without all the drives attached. It is like BIOS doesn't know where to find the boot record.

Megahertz said:

With both drives attached to a SATA port and using F11 during POST can you boot win 10 or win 11?

Yes, I can boot to Windows 10. That's where I got the second screen shot of disk manager.

Anyway, I have my Windows 11 boot issue fixed. Apparently it was corrupted or something.
I used a Rufus USB boot with Windows 11 ISO file to boot up with all drives disconnected except for the Windows 11 disk.

I chose repair Windows link on the bottom left of the Windows 11 install screen. Windows 11 waits a few minutes and informs me that Windows cannot be repaired. I had the option to go back to advanced where the options to install Windows 11 or continue to boot into Windows 11.

Oh a whim, I choose to boot into Windows 11 and it booted up. I don't know if Windows did the repair or fixed some thing else.

I do appreciate you generous offer to assist me!