CoD 2 Online?

When I join a server online on CoD 2 it says.
Error
Impure Client Detected. Invalid IWD Files referenced
c:/cod2/main/iw-00.iwd
what do i do?
Answer #1
Do you have a legit copy or a pirated one? If its pirated, then you won’t be able to play the game online on official servers.
Answer #2
maybe you have pirate DVD/CD
Answer #3
Try to visit some other servers.
Also try to reinstal the game.
Answer #4
Its pirated, what can I do to get cracked servers?
Answer #5
I have played CoD 2 online using a pirated version, but you should try more servers if you want to get in one, it’s not easy.