As many other people, I had problems getting my Fallout 3 GOTY to work on my windows 8 computer (I probably spent 2 or more weeks surfing the internet for solutions). but I finally got it to work with these exact steps
1) install fallout 3 GOTY
3)Then go to Program Files (x86)/Steam/steamapps/common and put the file into Fallout 3 goty
4)after that, go into Fallout 3 goty, right-click FalloutLauncher and select Properties, go to Compatibility, click "Change settings for all users", chech the box for "Run this program in compatibility mode for:" and change it to Windows 7. Click Apply
5)now Right-click Fallout3 (same folder as previous file) and do the exact thing but this time change it to Windows Vista (Service Pack 1)
6)now right-click Fallout3-Garden of Eden Creation Kit and do the same but the Compatibility for Windows 7
7)right-click GDInstall and do the same thing but change the compatibility to Windows XP (Service Pack 3)
8) go into the VCRedist folder(found in the Fallout 3 goty folder), right-click vcredist_x86 and change the compatibility to Windows Vista(make sure to update your vcredist_86 file first)
9) go back to the Fallout 3 goty folder and go into DotNetFX, right-click dotnetfx3_x64 and change its compatibility to Windows 7
10) Download GFWL(Games for Windows Live)http://www.xbox.com/en-CA/LIVE/PC/DownloadClient
11)now go into your Fallout3 folder(located in the Fallout 3 goty folder) open FalloutPrefs and change everything to this
sD3DDDevice="(put what ever type of Graphics card you have in this space)"
11-2) you might have to add some of the codes in and then click save
12)exit out and start your game, then change your Auto-save settings off(you will have to save manually for now on) then click NEW GAME.
SOMETIMES WHEN YOU TURN YOUR GAME ON IT WILL CRASH AS SOON AS YOU LAUCH THE GAME BUT ALL YOU HAVE TO DO IS LOG-OUT AND RESIGN-IN AND TRY AGAIN. WILL WORK AFTER TWO OR THREE TIMES(who knows, you might just get in on the first try every time)