I had one heck of a time getting F3(retail) to work on win10, here's what worked for me. I downloaded Fallout3_101 rar which includes the 4gig patch and fose which is a script extender for F3, Instructions for both are included in rar file. Oh yah you will nee games for windows live, I got v 3.5.56.0. Followed all instructions then when I tried to start game it said I had to update it so I did and now the only way Iit will start is to start update I downloaded which will come up with an error and before I can check it the game starts. Weird HUH? But game runs great saves are good so that's the way I am using it, why mess with something that works, I put a shortcut to the game update on my desktop lol.

I just got the game and it wouldn't launch, so I did what Bethesda said and ran it as an administrator and then I installed GFWL, and the game finally worked... up until I tried to create a new game and get started. At that point, the game would just crash. (I am on win10)