What's a compatibility mode?

I've downloaded driver thing. Its still running crap.

I don't know if this relates in some way to it, but I brought the game from the shops. Every time I start defcon it asks for my auth key, even though I entered it before and it said it was valid.

Would I have to buy a new driver?

Hi all.


I'm running defcon on windows 7 and its running slow. I've tried all the obvious things, like setting the resolution low and detail. I've installed the latest patch too. But it's still crap.

Can you help?