I just finished posting on another form and now I've signed up here because that fourm is really unactive. BTW i bought the game in the 06 collection from walmart so I know it's legal. When I first installed the game it worked fine but after playing for a while I decided I wanted to play online so I followed all the instructions then it told me to enter my reg. key so I did and it said it wasn't valid

I used the same key I installed the game with but it just won't work is there anyway to fix this?!