I am able to launch Toad and connect to a database, but when I connect the whole application goes away. It still shows in the task bar, but it is not visible on the screen.
It has something to do with the use of dual monitors.
1) After Toad disappears, select Alt+Space Bar on your key board.
2) Select the Move feature and use the arrow keys on your keyboard to move Toad so it is visible.