Thanks so much — this is helpful.

The product we purchased through TechSoup is specifically “Windows Pro Full Operating System – No Software Assurance (Computer Labs Only).” My understanding is that this is the special nonprofit full operating-system license rather than the usual Windows Pro upgrade license. We were provided one MAK key intended for all 10 computers.

I also checked Microsoft's nonprofit documentation, which says the TechSoup full Windows Professional grant is currently Windows 11 and includes down-level rights to Windows 10, so I believe the MAK I received should be for Windows 11.

I definitely performed a clean install, not an HP factory reset. I created Microsoft Windows 11 installation media on USB, booted from it, deleted all existing partitions on the internal drive, and installed Windows 11 Pro onto the unallocated space.

After installation, winver identifies the OS as Windows 11 Pro, but Windows is behaving as though it is still in S mode. Attempting to run Command Prompt says Windows only runs Microsoft-verified apps, and the Activation page says “Changing the product key isn't available in S mode.”

when i click open store i get a message " This upgrade isn't available for your version of Windows"

That's the part I can't explain. The laptop originally shipped with Home in S mode, but after wiping the drive and clean-installing Pro, Windows still appears to be enforcing S mode.

Got it. Thanks for double checking and glad you have the Windows 11 with downgrade right.

In this case, license is not the issue.

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Do you still have the USB flash drive that contains the installation files? If so, I am going to have you modify that flash drive. On your computer, launch the Notepad app and place the following in the file:

[EditionID]
Professional
[Channel]
Retail
[VL]
1

Then choose Save As and choose file type "all ..", then save it as

EI.cfg

in the file name field. And then place this file in your flash drive under the \Sources folder.

Then new another file in Notepad, and put this in the file (replace the Xs with the actual MAK key)

[PID] Value=xxxxx-xxxxx-xxxxx-xxxxx-xxxxx 

And now save it as PID.txt file. No need to do the Save as this time. Put in in the same folder.

Now do another round of clean install. See how it goes.

Thank you. I actually already tried almost exactly this on the second clean install.

I created both EI.cfg and PID.txt in the Sources folder on the USB. PID.txt contained the MAK key, and EI.cfg contained:

[EditionID] Professional [Channel] Retail [VL] 0

I then did another complete clean install, deleting all of the partitions on the internal drive first. Windows installed as Windows 11 Pro, but I ended up with the same S mode/activation problem.

I notice that your instructions use [VL] 1, whereas mine was [VL] 0. Since I have now confirmed that the key is a MAK volume-license key, could that difference be the cause of the problem?

I would rather confirm that before doing a third clean installation.