This error mentioned at the top - quoted below" - is exactly what I experienced as well: "I downloaded TES4Gecko earlier today, but it doesn't seem to work for me. I have the shortcut set up correctly, and the application does run. However, I always get an error message saying: Exception during program initialization java.io.IOException: Unable to locate Oblivion installation directory TES4Gecko.Main.main(Main.java:145) Using the magical powers of google it seems the problem is because I use a 64-bit computer. Can somebody give me instructions on what to do to fix it? Help will be greatly appreciated" Thanks to chaospearl and RMWChaos for their great info. It is greatly appreciated! I have a 64-bit computer with Windows 7 Professional and this helped perfectly. Kudos Guys!