If you open a new Integra window and it does not appear it may have opened on a monitor that is not connected.
The following can be used to bring the window back to the main screen.
Alt + Spacebar to bring up the menu.
Then select move (M key) and use the arrow keys to try to bring it back into view. (you can move it farther off the screen so I recommend holding down the left arrow for 8-10 seconds and then right for 18-20 seconds if it does not appear going to the left.