World of Warcraft could not be found. Please

This will happen if you do not have the correct registry keys for the patch to find the game. Make sure you have administrative rights and that you don't have any programs blocking any registry key writes. If they're fine, run the Launcher and it will force the registry keys to update (or be created if you had none), then it will start up the patch and point it to the right place.

Q u o t e:
PS: Why am I on Greymane and in Manifest Chaos? I haven't been on that server for months now.

Try selecting another character on the upper right login thing by clicking on your character portrait, and back to that character. Should refresh it.