for me normally when i start the game, it goes black for a few seconds. if i click on the screen in that time it comes up with the windows 'this program is not responding' prompt, but it continues after a few seconds.
update to the latest ati drivers for your graphics card, are there any other games that have this problem for you?
if reinstalling doesn't help and validating the game cache doesn't help it's probably not a software issue.
BUT!!! Before you install GFWL, uninstall Dirt 3 and do not download it or install it yet. Now install GFWL and make sure you've logged into it at least once and you're able to see stuff within it.
Now download Dirt 3 and install it. Make sure you do not have any of the "fixes" that you've tried so far and that the game is running like it should normally. No compatibility modes or anything. When you start the game you will get the GFWL login asking you for your key, input it and you'll be good to go.
I would have just reinstalled windows by now. Having a lot of GFWL titles myself i have had these problems and all were fixed with a format and reinstall
I agree... but if you like miss one step when re-installing, then you'll be on the same boat. I tried playing Dirt 2/3 with the GFWL installation that comes with the games and they just crashed. Until I did what I mentioned above. This was right after a fresh windows 8 install too.