Wrong disc inserted
 

I just got the game as a gift from my brother, and I've played it for a few days without issue, until just now when I found this website and the patch. I downloaded and installed patch 1.7, and now when I go to start the game, I get this error;

"Kings Bounty

Wrong disc inserted.
Please insert the original "Kings Bounty" CD/DVD.
Please have a look at http://www.securom.com/message.asp?m=wrongdisc for further, more detailed information."

The game is on a single DVD, so it's unlikely that it's the wrong one. Any idea what to do about this? Or will I have to reinstall to revert back pre-patch? And if so, where's the save file?

There are different patches for different versions of the game. Who is the publisher of yours?

Atari, I think. www.kings-bounty.com/eng is the url given on the back of the box and mandual.

Ah, I see, I need to use this 1.65 one?