I've been dealing with the "Fallout3 has stopped working" issue with 64-bit Windows 7 desktops. I bought the Fallout 3 Game of the Year Edition via Steam (for $10 on sale unbelievable). I don't know where I found this but I changed my Windows theme to the Windows 7 Basic theme. The game actually launched at this point. I didn't start playing it, but at least I got it to start.
Hope this gets you started in the right direction.
~AllSystemsDown