Well, I'm running Windows 7 and have a Radeon HD 6950 graphics card. At first, I just couldn't get the game to launch at all. Installed it, double-clicked the shortcut, nothing.
Thanks to a few others posts here, though, I finally figured it out. Since I guess a few others might be almost as stupid as I am, here's what I did, step by step:
1. Find the Soulbringer.exe file (and not, as others have already correctly mentioned, the shortcut).
2. Right click on it, choose "Properties", and the properties window will pop up. There, click on the "Compatibility" tab.
3. In the compatibility window, choose to run the program in compatibility mode for Windows 98 (Windows 95 also works). In the same window, in "Settings", you can leave all options unchecked. Finally, at "Privilege level" (again in the same window) check the "Run as administrator" option. Click "OK" to leave the properties window.
4. Now doubleclick Soulbringer.exe. If all's well, the Soulbringer launcher window will pop up. Here, you can experiment with various video settings.
Now, I'm not quite out of the woods yet. For example, the text in the game is difficult to read. However, the game does run!