Renbean: I downloaded DirectX End-User Runtime Web Installer, and after I run the installer I get the message "DirectX setup has determined that a new or equivalent version of DirectX has been installed already. No installation is necessary."
Did I install the right one?
If you used the link I provided, then yes. Message probably mean some game already installed it (lot of bigger and most retail games come with nessesary libraries) so that part is probably ok. You can try the
redistributable version if you wish but it should not make any difference.
Renbean: I just installed the latest version of sfall, extracted 'ddraw.dll' and 'ddraw.ini' into the base folder and the game boots up fine up untill the first cutscene, I now see a green rectangle on the screen when the game freezes.
One more thing you could try is change the ddraw.ini [Graphics] setting from Mode=0 to Mode=4 or Mode=5. If that does not work you might as well try Fallout 2 Unofficial Patch or Restoration Project from
http://killap.net/. As others have said you should not need to but if all else fail, I see no harm trying it.
If even that does not work I suggest contacting GOG support as your problem is really uncommon (did not find ANY mention in various places I looked). Descripe the problem to them, provide your system specs and link to this topic so they can see what has already been tried. If they can't help you, probably no one can.
I've read that the "rainbow color"issue is pretty common in some Fallout 2 era games when running them in Vista or newer operating system but I've never heard it preventing running of game (it makes the game unplayable ofcource due to messed up colors). Because I've never witnessed it, I've never had to resort to the workarounds for the issue nor seen wether or not they work. One workaround is "just right click on the desktop and chose "screen resolution" and let that window be open then start the game." It won't help game freezing at startup.
Sorry I could not be of any more help but after the above you've have tried pretty much every workaround/fix I know for this game.