MelaneeofGOME 19 Gru, 2013 - 7:13
Helpful Tips: Fixing Issue with Windowed Mode Bug
Go to My Documents > WBGames > Guardians of Middle-Earth.

Open up the Settings.cfg file with Notepad or Notepad+

On line 3 you should see "Fullscreen" and beside it it should read "False" because it has been set to windowed. Just change "False" to "True" and that should resolve the issue!