Get the window back first of all. Right mouse click on the pop up bar at the foot of your screen and select "cascade windows". Now get and resize your window to a workable size and position.
Then go to the icon that starts E.G. and right click and select properties. Look for the window size tab, and select the size you require. It will be maximized, normal or minimized.
Now reboot your machine and make sure the settings persist. If not, you should explore the net looking for fixes for window sizing, rather than E.G.
Good luck
David