Have you tried running the game with adminstrator rights for the first time yet.

Win 7 is nice OS but it still has the crappy UAC when you install a game into the program files and the game loads up for the first time and changes files.  With UAC on for win 7 or vista this stops games from doing this.  Hence the reason you have to run them the first time with Adminstatrator rights.

Please open your debug.err file in notepad, and copy/paste the contents into a post here. This will give us some technical information that can help troubleshoot your problem. The location you'll find the debug.err in varies depending on which game you're playing:

Dread Lords: My Documents\My Games\GalCiv2
Dark Avatar: My Documents\My Games\GC2DarkAvatar
Twilight of the Arnor: My Documents\My Games\GC2TwilightArnor

Older versions may store the debug directly in the location the game is installed at.

Be sure to copy the debug immediately after the error occurs; if you start the game again, the debug will be erased and recreated for the new session.

That is one crappy response. UAC in Win7 is not crappy, and it has similar principles as in Linux or Mac OS X.

I'll never understand you people, bashing M$ products over and over again, even though it's getting what you've asked - more security. The problem with Administrator rights required is caused by badly written software, which is often trying to do things it shouldn't, like write to 'Program Files' or other secure locations.

As for the Win7 UAC, it's much more user friendly now, because you can tweak the amount of messages you'll ever see on the screen.

Cheers.

I'm gonna guess you're running dual screens...I've been having the same issue since I installed Windows 7 64bit.  It worked fine in Vista 64bit dual screen mode.  I could even keep the CPU gadget on the second monitor so I could see when my resources were getting low.  Disable the second screen in Appearance and Personalization and see if that fixes the crash.

Attention Stardock: Please patch this problem.  This fix must only be a temporary work-around and not a permanent solution.  I want to use dual screen mode!  Thank you.

Fullscreen works fine for me on 7x64 with dual monitors. Most people who've had this issue have driver failures in their debug.err files and can solve it by using windowed mode until proper drivers are issued.