"Launcher requires write permission to the world of warcraft Registry key to successfully locate and run the game. Please enable write access to the Registry using an administrator account."
I am the administrator and only person who uses this account. I did the right click to "run as administrator and I got the same message. When I went back to check on my account just to make sure the upgrade took, it does say World of Warcraft Wrath of the Lich King account active. Prior to this upgrade, I was able to log into WOW just fine.
Anyone know what else I need to do?