Fallout 3 does not appear to be installed and the installer could not be found. Try exploring your DVD-ROM drive and selecting setup.exe to install the game.
Now I have a Steam build of the game, so it'd be impossible for me to install the game, other than re-downloading it. If anyone has any ideas, please tell me.
I don't really need the launcher. I just like to use it to change some of the video settings, which I can always do in-game (I think). Thanks for the help.