Older HP notebook HP Envy 17T-J000 Windows 8 activation- Windows OEM not present in firmware

[GuitarPicker]

Hello All,  after a successful recovery back to Windows 8 from the refurbisher's install of Windows 10 x64 the Windows OEM key is not present in the firmware when checked in the BIOS settings.  I either need a new windows 8/8.1 key or the original which was wiped when the refurbisher changed it to Windows 10.  I ordered the Windows 8 recovery discs from a third party HP recovery media reseller and the BIOS either did not pick it up or Microsoft deactivated the original number.  I do have an installed key in the BIOS but I believe it may be for Windows 10.  I tried the phone method and the automated response says they cannot give me a number to activate that edition.Is there a way to find the original key off of the software discs?  Any help would be appreciated.  Once I get it activated I eventually would like to upgrade to windows 8.1 Pro x64.....Thank You

[GuitarPicker]

As an update to the product I.D. number....I was able to do a script command and save it as a vbs file from the registry and it is indeed a different number that is displayed from ShowKey that is said to be in the BIOS but is not the embedded BIOS number.  This is also a 25 character number so presumably it's the OEM product I.D. number and I tried to enter the number as an upgrade and it will not take it.  I tried to get a live telephone representative from Microsoft however they may not work on the weekends or it is a non existent service these days.  I don't know how long this installation will work with the watermark and notice saying I have to activate.  It's Windows 8 Build 9200.  Any ideas would be appreciated...Thanks