windows7 activation product key

I upgraded from windows 7 to windows 10 after formatting the computer I installed windows 7 again but when I type the activation key it is showing error code 0x80072f8f . The activation key which I have is genuine

I just purchased a second hand copy of Windows 8 Pro (32/64bit Upgrade Discs) from a small IT dealer, and it comes with a Product Key. I'm "waiting for the mailman" but I think it will provide a "Retail" version of Windows 8 when it gets used to upgrade my existing Windows 7 Home Prem' OEM...

Dears, Good day, I have Asus PC with built in window, i am trying to boot recovery mood f9 when the PC start off. unfortunately the recovery not solve the problem even when i select full format for PC. the PC run and shut down again and again (unlimited loop) seems that there is a software...

My computer has been saying it needs activation, so i tried to activate it with the product key under my computer (for a windows 7 home premium) and it wont work, my computer says it uses windows 7 ultimate and i dont know how to change it.