I got Nebula to work but it's not that pretty. First, set up Nebula to load up using "Fullscreen GUI" this can be done in the "Options" menu under "Emulation" when you first start Nebula or you can open up "nebula.ini" and look for "GUIMode=1" Change the "1" to "0" for "Fullscreen GUI." (1 is for "Window GUI" where as 0 is for "Fullscreen GUI") Next, just set up Nebula as an "External Application" in GameEx. When you start GameEx just go into, "More Games & Programs" and launch Nebula from there.