Remove Extra Game Profiles
For whatever reason you may get multiple game profiles for the same game. If you multiple box you usually have different addons for each account and this will help you manage each one separately. However, if the reason you have two or more is because of something like reinstalling the game or moving it to a new drive you may not want the extra profile lurking about in your Curse Client.
For assistance with Game Profiles check this guide.
How to Get Rid of the Extra Profiles
You are going to want to hide the extra profiles so that the Curse Client doesn't manage them any more.
Locate the extra Game Profile you want to remove. In this case it's an extra World of Warcraft profile.
Right click on it and select Hide.
It is now disabled. and the Curse Client will no longer manage it. It will also disappear from your list.
Undo the Above
Say you disabled (hid) the wrong Game Profile. This is easy to fix. Just need to Enable it again.
Go to Tools > Add a Game > Games & Addons tab.
Cancel out of the Browser window that pops up.
From the Select an existing game: drop-down select the Game Profile you want to enable. In this case would be World of Warcraft 2
Check the Enable box in the Game Settings.
The Game Profile should appear back in the list, and is being managed by the Curse Client again.