Sorry I have made a mistake there is no such thing as steam on GTA4. I thought it was but it was Rockstar Social Club Games account you login to, I have played a copy and liked it so I bought it. You can add games to steam as non-steam games, but for steam achievements and stuff even if you buy from steam you will not get these apart from few games like some Half-life and counter strike etc because the are made by valve who bring you steam. Sorry for confusing anyone. As of the Games For Windows issue I phoned up a number for United Kingdom support on Games For Windows Website and the number is actually for Xbox Live and they cannot help you. At first I was told to phone up Rockstar and did and they said it was a Games For Windows issue that the CD-key isn't accepted logging into Windows Live. I was going to buy from steam but it's 25 pounds, here it's 18. For other games it's like 20 pounds when you can get for like a 5er on https://amazon.co.uk. But for GTA4 you have to have the disc which is so annoying I used the 220.127.116.11 no cd to launch my 18.104.22.168 (latest version) I thought I fixed it changing compatibility mode to Vista Service pack 2 but it turned out it was a fluke it managed to work first attempt in Vista mode. It turns out it's like a 1 in 10 chance to load maybe(it says not responding and closes itself)? And even with the disc in with normal launcher it doesn't begin to load lots of times but when it does it's fine. This would probably be the one game you might want to buy straight from steam to avoid having to use discs and have cd key issues.