I had a not genuine windows when my windows was hacked. My boyfriend bought me a new Windows 7 Ultimate (same version as before) and sent me the product key only (not the installation CD since we're far from each other). My question is, how can I change the product key? I tried the normal process of changing the product key but it doesn't work. This error showed up, "User Account Control(UAC) has failed to authenticate the user. Error code is 0x8007076B". Hope you can help me.Thanks