I did see a few guarded comments when I downloaded it, the inference being that you need a fairly pokey machine, or at least, a fairly recent one - to run it.
Two things here. If you look in the program folder for GE, there are options to run it under Direct X or Open GL. Whichever you are running, try the other. Failing that, get yourself armed with the latest drivers for your video card and that should help.
If it doesn't work, come back here with details of your video card and we can scratch our heads a bit.
Good Luck!
Conan