From AD onwards, graphics card reports error

[NewbieCivFan]

Hi all,
Pleased to be joining your great forum. Just downloaded Civ IV from Steam and it's the first time I played it since Civ I many moons ago - got too addicted back then and gave it up so I could finish college. Guess it's time to re-make old mistakes.
So, loving the enhanced graphics and more complex AI interactions - tho' it's taking me time to work my way through the new city screens (guess I'm getting old).
Everything has been running fine, then when I hit AD, I've got a nice little empire of six cities and the game shuts down.
Windows tells me the graphics card is reporting an error so Windows has shut it down. When I re-boot my machine, the load up whilst the BIOS is kicking in has these funny $ signs everywhere and there's obvious graphics problems. The card hasn't been re-activated. I check that the latest drivers are installed, it says they are, and I re-boot again - everything's now fine.
Back to the game - a few brief turns and the same happens again.
So, your help, advice, wisdom much appreciated so I can once again ruin my brief leisure hours building the world as it should have been.
Many thanks all
A

Windows 7 Home Premium 32-bit
Intel Q6600 2.4 Ghz quad-core
3Gb RAM
GeForce 8800 GT
(DxDiag attached - I think!)

 

[NewbieCivFan]

Folks,
Just played again to generate more info on error messages (after reading some more of your other threads).
Exactly same happened within a few turns and the following appeared when Windows recovered:

Problem Event Name: BlueScreen
BCCode: 116
BCP1: 8619E008
BCP2: 9050CA50
BCP3: 00000000
BCP4: 00000002

It also references two files with additional info contained (051510-54865-01.dmp from the Windows Minidump folder and WER-87703-0.sysdata from the Users Temp folder) - if you want them I'll attach them, but they're a couple of Mb so didn't want to do that until someone says they need them.
Thanks again for any insight.
A

 

[NewbieCivFan]

Ok folks,
I turned off the unit animations and have now played a blissful, crash free hour.
Unless I have a recurrence, please consider this closed.

Enjoy!
A

 

[MarkJohnson]

It may be your card is old and dirty causing it to overheat. Try buying some canned air and blowing out the inside of your computer and getting the video card really well.

good luck
-=Mark=-