I've checked everywhere even the disk (since its a DISK key) but i can't find it! Where is the disk key?

If you have the Codemasters version, email Codemasters here: http://www.codemasters.co.uk/support/contact.php and they should provide a key - I think on some Codemasters versions there was an issue with distributing the keys...

If you have the Majesco version, go here: http://www.majescogames.com

The German (Codemasters) version comes in a DVD-box, which contains, the DVD, the printed manual, a little book advertising other Codemasters games and an extra piece of paper that explains the disc key in six languages and has the key printed at the bottom.

So if you have a legal copy of the codemasters version it should be the same.
If not, take it back to the place where you bought it.

If you have the Majesco version (US), it might be different.
As you say you checked everywhere, this probably won't help, but here are the usual places:
On the disc itself (you already said it's not there).
On the back of the manual.
Inside the manual. (Just so everyone reads it carefully)
On the inside of the DVD-box.
In a file on the disc (Like the readme file).

Once I bought a program, that was accidently shipped without the key inside. I e-mailed the support and they send me a key. If you can prove that you really bought your copy legally, Team17 or Codemaster / Majesco, don't know, who is responsible might send you one. However it's probably easier to take it back to the store.

I guess I wrote to much, thomasp was a little faster.

In a file on the disc (Like the readme file).
that's just pirated games. all disks are printed with the same data, so if you put a file on the disk with the key, each copy will end up having the same one.

I've checked everywhere even the disk (since its a DISK key) but i can't find it! Where is the disk key?
It's on that little grey leaflet inside the box.

that's just pirated games. all disks are printed with the same data, so if you put a file on the disk with the key, each copy will end up having the same one.

I was just talking in general.
In the good old days, some games had little decoders for passwords (like the wheel in Monkey Island). Others asked for things like the "third word on page 15" of the manual.
Sometimes you find such games in classic-games collections, but they don't print out manuals anymore, just put them in a .pdf on the disc.
For some programs that come with computer magazines the key is also in a file on the disc, but then it probably is the same for all users.

But you are right, searching the disc for files with the key is rather useless with modern programs.

In my codemasters version, it is a little orange sticker just above the place where the DVD goes, labled "DISK KEY" with a little key icon...
Although I preordered it and got it the day when it came out...

Just so you know... the majesco version doesn't need a key :p

My suggestion is that you write the Disc Key somewhere else... in case you lose the actual copy.