I installed both last night and have only run Riven twice to see if it would run. Really strange, when I exited from the game to desktop I couldn't access any of the folders on it. They would appear in the task bar but would not open, I freaked out big time. I could open progs from the START menu but not the desktop.

scratching my head and making a few calls I had nothing. Eventually I stumbled onto the issue, Riven shoves the working window, (lack of correct term) down off the screen when it loads or when you exit the game. I began clicking on the options that appear when you have the thumbnail at the bottom of the screen. Click restore then move then, (not sure exactly yet about the next part) click the up directional arrow and then press and hold the left mouse button and slide the mouse up. the hidden working window pops up from the bottom of the screen.

Not sure yet whether you need to press the arrow key or not.