So Dirt 3 Wont Start …
Here is how I fixed my problem in Windows 7.
1) Locate your Dirt 3 folder. Should be something like C:Program FilesSteamsteamappscommondirt 3
2) Right click dirt3_game and run as administrator. Did you get an error like this: “xlive.dll missing” If it mentions anything about xlive.dll then this here will most likely be yor fix.
3) The xlive.dll comes in the “Games for Live” package from Microsoft. This is the download link: http://go.microsoft.com/fwlink/?LinkId=128962
4) No need to restart, try running from steam again. For me this worked.