unit684 wrote:I got a response from introversion. They said that if I reinstall and enter the key again it should work but I have tried reinstalling and as I downloaded it with steam it has no key.
You do have a key, Steam just handles the entering for you. You might want to try this: Uninstall it, go to your Steam directory (I think that's where Steam places this file) and delete the authkey file. Then reinstall.