so i bought fallout 3 on steam and apparently its not optimized for windows 8, ive looked for the compatability mode in the properties pop-up but the option for it is not there, its just a shortcut to steam and shows the ID to the game. i need help to fix this or i just wasted my money on a faulty game.

You set the compatibility on the EXE in the install directory. Note, also do this to the Launcher.

But, did you install this game properly?

http://www.gamesas.com/topic/1465357-installing-fallout-3-with-windows-78-and-xp/