I tried a couple of keys (took the first game back to best buy and exchanged it because I thought that one was just bad) but it refuses to accept the cd key no matter how many times I retype it. I know I'm not confused, I even had my friend try typing it in for me, so I've got two opinions that say I'm typing the key right.
I've read the other threads on it, I originally installed the game to my external drive, but tried reinstalling to C: after reading about people having problems with not using C: I've retyped the key over and over, and it just refuses to take it. It did make a My Games\Unreal Tournament 3 directory, so that's not it.
I know the keys are good, too. My friend also bought the game, and when he came over to play and saw I was having trouble, he swapped keys with me (before he installed his copy), and he was able to install on his computer using the key from my game that my game refused to accept, but the key from his game won't work now.
There's something wrong with the cd key stuff, but I have no clue what.
I am not sure, but mine accepted the key. But then just today it asked it for me again. That made me nervous in a way. What is weird was, I chose the destination drive as D: but the game installed it on C: anyway .
Maybe try removing and reinstalling. Make sure you clean out all your folders.