It says on this app that the game is optimised for Win 10 ; but when i launch it and try to start a new game ; the fuckin thing just crahes. Do i have to go into the games files or something to to turn on the Win 10 support. At this point i might as well just buy a Win 7 computer and play it on there.

The game will not run unaided on systems with integrated Intel graphics. There is a bypass workaround, but my machine still refused to run FO3 (even though it ran FO:NV without problems) with the bypass installed. I therefore set it to run on my GTX1080 and set it to Windows XP compatibility. That got it running. But Intel graphics is the bane of many a game, and FO3 is notorious for that.

@ZeldaMaster20143, that's what I ended up doing. It would constantly crash on me when I tried running it on Win10, and that was with an AMD Radeon R7. I reverted back to Win7 on that system and everything ended up working just fine.