Rosaamarilla For the issue with Dragon Valley, please see the first post of this master thread:
Sims 3 Store world can't register/install | EA Forums - 11143823
For the game itself, please move the entire Sims 3 folder out of Documents > Electronic Arts and onto your desktop. If it copies instead of moving, or you get an error when trying to move it, stop here and let me know.
Otherwise, try to play, which will create a new Sims 3 folder, that is if the game opens at all. Let me know whether this works and if you can get far enough to start a new save. Your previous saves won't be available, as they'll be in the folder you moved, but you can restore them later.