Uninstall the game if it's installed then run ccleaner (free software, google it) after you uninstall it to remove any lingering registry entries. Also do the typical, delete the game folder ect.

Try creating a new folder (you can name it "games" if you want) and then try installing the game to the folder instead of the default location. Make the new folder outside of program files, it can be right inside C: drive where the windows folder is. This fixes a lot of issues with videos games in Vista, especially older ones.

See if that helps any.

This worked for me:

1. Remove things like webcams and xbox controllers for windows(I've no clue why, but it seemed to work after I removed mine at last, though it could be the following)

2. Uninstall Demigod completely, run CCleaner to remove temporary files, fix all registry problems, manually remove any and all leftover folders that may or may not be present, depending obviously on the alignment of the planets and the mood of your favourite deity, aswell as operating system.

3. Remove any useless startup entries with CCleaner, just to be sure, though you should do this anyway. Google any processes you're unsure of(eg. try not to mess up your whole OS installation with it)

4. Uninstall video card, sound card and network(if applicable) drivers, run DriverSweeper in safemode, install latest drivers.

5. Run CCleaner again to make sure there isnt any useless junk sneaking back on.

6. Install Demigod, scream accordingly if it still doesnt work.

Minus the astrology part, that's roughly what I did and it started working there and then.

I had some strange problem with Demigod throwing an error before even launching properly and then the glorious "This application has stopped working".