Activate Windows 8.1 Retail Windows 8 product key.

Hello. How do I understang of Search and Google that its impossible to get real I have win8if key from another PC preinstalled. Story is that I 2 Windows7 keys, but my friend bought new PC with preinstalled Windows 8. He did not like and ishare one of my win7 key and received from him 8 key, what we get from BIOS, win by rwtool. But I do not have a recovery DVD, so I try some of the network, but button does not work. Is there a solution for this? Thanks in advance. Hello. How do I understang of Search and Google that its impossible to get real I have win8if key from another PC preinstalled. Story is that I 2 Windows7 keys, but my friend bought new PC with preinstalled Windows 8. He did not like and ishare one of my win7 key and received from him 8 key, what we get from BIOS, win by rwtool. But I do not have a recovery DVD, so I try some of the network, but button does not work. Is there a solution for this? Thanks in advance.