The GDF file is an xml file associated with games in vista. The file gives information about the various ratings associated with the game along with the name of the game. The XML file format is fairly simple and is as follows:
<GameDefinitionFile> <GameDefinition> <Version> <VersionNumber versionNumber="x.y.y.y" /> </Version> <Name>name of game</Name> <GameExecutables> <GameExecutable path="xyz.exe" /> ... </GameExecutables> <Ratings> <Rating ratingId='<rating guid>' ratingSystemID='<rating system guid>'> <Descriptor descriptorID='<descriptor guid>' /> </Rating> ... </Ratings> </GameDefintion> ...</GameDefinitionFile>
Here is a simple C# class to read in and parse a GDF file. It assumes you are given an xml file as an input.