This is intended to be helpful to those left scratching their head as to why they ended up back with the Windows 11 Home version their machine was originally retailed with, and not for example, with Windows 11 Pro which they had upgraded to themselves and has a valid Pro digital licence registered with Microsoft’s activation servers.
Why does a fresh install revert your Windows 11 Pro version back to WIndows 11 Home?
When the PC originally shipped with Windows 11 Home, the OEM Home key was embedded by the OEM in the UEFI firmware (not user modifiable). Windows Setup then reads this key and automatically installs Home, even if the machine had been upgraded to Pro and has a valid Pro digital licence.
There are two simple files you can add directly to the \sources folder of the Windows installation USB, or into the \sources folder within the ISO if you’re using Ventoy to make Setup offer all available Windows editions.
Create a file called ei.cfg in Notepad containing:
[Channel]Retail
[VL]0
Save it as ei.cfg, (make sure Notepad hasn’t actually saved it as ei.cfg.txt) then copy it to:
\sources\ei.cfg
If you specifically want to force Windows 11 Pro, create a file called PID.txt containing:
[PID]
Value=VK7JG-NPHTM-C97JM-9MPGT-3V66T
Copy that to:
the \sources folder of the Windows installation USB, or into the \sources folder within the ISO if you’re using Ventoy.
The key above is Microsoft’s generic Pro installation key. It does not activate Windows or provide a licence, it just tells Setup to install Pro. If your PC already has a valid Pro digital licence registered with Microsoft’s activation servers, Pro will activate automatically once online.
In short, ei.cfg gives you the edition choice, PID.txt directs Setup to Pro, and you can use both if you want to make absolutely sure the embedded OEM Home key doesn’t dictate the installation.