Just bought the game on GMG and like a lot of people I was having some trouble trying to get the game to run without crashing. Fortunately I was able to find a fix by scouring the internet! So here's a nice Windows 7 checklist to run off if you're having troubles too.
-Make sure video card drivers are up to date (duh)
-Make sure PhysX driver is up to date
-Go to Sacred 2 Gold/system and set "sacred2.exe" as well as "s2gs.exe" to run in compatibility mode for Windows XP SP3 and run as admin in the properties menu
-Go to your steam library, right click Sacred 2 Gold, click properties, click on "set launch options..." in the general tab. Enter "-skipopenal -nocpubinding" (Without the ") into the text box and press OK
-Install the community patch which can be found here: http://xmas.ancaria.net/patches/cm-patch0140hf.zip
-Go back into "sacred2.exe"'s properties and select "Disable visual themes" and "Disable desktop composition" in the compatibility tab
If you have a fix that isn't here please post it! Let's make as many people as we can able to play the game!