Here are the specs for your HP Pavilion 20-b010 All-in-One Desktop Computer. This model shipped with Windows 8 installed. The Windows 8 OEM key will not activate Windows 8.1. Windows 8.1 Should automatically be activated during the upgrade process via the Microsoft Store.
What is the exact issue you are having??? Why do you need the Windows 8 product key??? How did you install Windows 8.1??? From where did you get Windows 8.1??? What are you trying to accomplish???
If you have any further questions, please don't hesitate to ask.
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