When I launch G.E.C.K. only the Cell View window comes up. So far I've uninstalled and reinstalled G.E.C.K. twice. I then updated to 1.5, and still the same problem. Can anyone help me out here?

Click the View menu to select which windows are shown.

There's no View Menu. I have only one window appear. That's Cell View. Nothing else. It pops up as a lone window, and gives me an option for Interior or Wasteland under world space.

Did you try loading the game resources? Like Fallout3.esm?

There's no top menu. There's only one window, the Cell View window which pops up. I've no idea how to load anything, as I only have a Cell View window. There's no Menu on the Cell Window, only a spot for coordinates, and a dropdown for World Space (Interior or Wasteland). This doesn't look like any of the pictures or videos I've seen of the program, as they have multiple windows and a top menu, ect. I just have Cell View window. And uninstalling and reinstalling G.E.C.K. doesn't seem to help.

Alright, Just in case someone suggests it, I've uninstalled and reinstalled Fallout 3 as well. The same problem is persisting...I'm out of ideas, does anyone know how to fix this problem? The only thing that comes up (period) when I run GECK, is the Cell View window. Nothing else. No options at the top, no top bars, no drop bars, nothing but that window.

Have you tried to alt+tab and/or ctrl+tab to get the main window to pop up?

There is no main window. I've tried alt+tab and ctrl + tab, and it just lists Cell View under the GECK icon (I'm using XP). There is no main menu, main window, just the Cell View.

Does no one know how to fix this, or what the cause is?

What you describe is impossible without something wrong with your computer, in my opinion. Without the GECK window open, you should not be able to see the Cell Window.
Did you install the GECK in the active game folder? Did run it in administrator mode? Did you mess with the 'ini' files in the My Games folder?