HP 300-020 repaired but HP did not provide reinstalled Windows product key

[CIAgency]

ISSUE: Can HP provide Windows 8.1 product key for HP Pavilion repaired by HP that was returned without new Windows product key?

BACKGROUND: Bought 6 HP Pavilions with Windows 8.1. One device would not power on. HP repaired then returned device (CSO ORDER # BHBB628001). Later installed free Windows 10 upgrade on all devices. However, a recent Windows 10 update crashed ALL our HP devices that had upgraded from 8.1.  Was able to recover all but this repaired devices with recovery backup. We were not aware a new incident of 8.1 was installed during repair so recovery backup included original product key that Microsoft does not recognize.

[itsmyname]

> Later installed free Windows 10 upgrade on all devices.

If you activated Windows 10 on that hardware, the activation process registered, with MIcrosoft, the product-key and characteristics of your particular device. So, if you download Windows 10:

   Get Windows 10 | Microsoft

and install from it, Windows 10 will "call home" and obtain the product-key.  

P.S. Note that the product-key may be embedded in the motherboard, and the Windows Installer will try to retrieve that product-key.

When installing, choose "I do not have a product key". If you have an Internet connection while installing, Windows 10 will automatically activate.

[CIAgency]

Thank you for the response. I've download 10 but cannot activate without current active incident of 8.1. The HP device displays the last 5 characters of a 8.1 product key so it is matched to new motherboard HP installed. But, Windows does not recognize this product key. Windows does however continue to update 8.1 while still asking to activate.   

I've seen this issue several times before with other repaired devices. Techs will load an unregistered copy of Windows that's not intended for retail use. It's usually not an issue because we can provide the repair ticket and get the correct retail Windows Product Key. Problem here is HP will not do this. 

[DGroves]

HP will not use a retail win 8/8.x (or any later windows OS) all hp Installs or reinstalls use a OEM image which will not ask for a key

however since hp makes hundreds of computer models it's possible that a system might display a enter serial prompt, but as a previous poster said windows 8 will either use the embedded bios key or contact MS servers for a key check, also note that this key check is not the same as a windows activation, that's the very next step after checking for a valid key or digital license

https://support.hp.com/us-en/product/hp-pavilion-mini-300-000-desktop-pc-series/7477739/model/753060...

HP cloud recovery tool

https://support.hp.com/us-en/document/c06162205

http://support.hp.cloud-recovery.s3-website-us-west-1.amazonaws.com/