Navigate to your Steam userdata folder: Steam\userdata\ \41070\local\ . Open with a text editor like Notepad. Locate and modify the following lines:
The "Cannot set display mode" error is not a sign that your PC is broken or that Serious Sam 3 is unplayable. It is simply a handshake problem between old code and new hardware. By forcing a standard resolution, clearing corrupted configs, or adjusting GPU settings, you can almost always get back to mowing down hordes of headless bombers in no time. serious sam 3 cannot set display mode
