Wasn't able to get a clear answer on this. I have a back up of both the Volume KMS Activation and Pro WMC Microsoft Key activation for my Windows 8 Pro WMC If I do a re-install of a Windows 8 Pro with the Retail key, Can I just restore the (KMS) activation on the retail as per guides posted online, or do I need to slmgr and install a Volume KMS key, before replacing the activation files to restore activation? If activation is successfully restored, it will be 180 days activated without the need to contact any KMS? And from there if I install the Pro WMC addon via the key that I got from Microsoft for the WMC free add on promotion, I should still be able to activate via online? It is on the same machine that had the key activated on. Thanks!