I just got windows 7 64 myself and tried installing a few mods. The issue I have with 99% of them is that my "game of the year" edition has no actual data file. Well, the file is there but nothing exists in it. So any mod that tells.asks for my to copy data in fallout3/data/whatever......all the nif files to be replaced simply aren't there. When I run the game with the fallout3 app as opposed to the launcher some core mods will run. When using fose it tries to load old game files that I thought were deleted after the patch. My system is run as administrator and I have hide files options turned off. It might just be the version of fallout that people have that determines how easy mods are to use.