Hi PortPro, welcome to the Seven forums.
This happens sometimes when Windows tries to open a window in a non-existing second display, for instance when you have had a second display connected which is then disconnected. To fix this is quite simple.
Do this, carefully and exactly as told:
- Open the application in question, see if it disappears right or left (right in your case, as you told). Do not click anything else as to keep Windows focus on that application window
- Press ALT + SPACE to open window context menu. Trust me, it opens although you are not going to see it

- Press ENTER to exit full screen mode. You can not move a full screen window using this method so this is important. If window is not in full screen mode, this does nothing else than closes the context menu
- Press ALT + SPACE to open window context menu again
- Press M to select Move on that menu
- Press and hold down LEFT ARROW if the window has disappeared to the right, RIGHT ARROW if the window has disappeared to the left
- Release the arrow key when you can see the window on your display, press ENTER
That's it. If you want to, you can practise this with a window that is visible on your display, to see what each of the steps described above does.
Kari