Cd key problems

[AndrewHambleton]

I've had CS for like 5 years now, but suddenly it tells me that I have to buy the game again or something. Every time I try to play, it takes me right to the store. I want to reactivate my game, but I don't know where the hell I put the case with the cd key on it. It's been a while, ya know? Anyway, I know there's something you type into the "run" function in windows that lets you view your cd key, but I just don't remember what it is. Can anyone help?