I just went out today and purchased HL2 Episode 1 (a little late I know but money doesn't grow on trees these days) When I went to install it I had to put in the product key which I found on the provided paper slip inside the case. I put it in several times double checking and making sure that I wasn't typing a character wrong and that maybe what I thought was a 1 was an L blah blah blah but it wouldn't work! Is it possible that the product key is defective? Help me out. I could go just return it and exchange it for a different game but I might aswell ask before I do. I want to have the game up and ready for a party tomorrow afternoon.