If you’re still seeing the error after trying the above, the problem is likely deeper—involving your Windows display scaling, GPU drivers, or multiple monitors.
You can bypass the error by forcing the game to start in windowed mode or at a specific resolution through its configuration file. Navigate to the folder serious sam 3 cannot set display mode top
The "Cannot set display mode" error in usually stems from missing DirectX 9.0c components, outdated GPU drivers, or a corrupt configuration file. 🛠️ Quick Fixes If you’re still seeing the error after trying
In Steam Launch Options, type: +fullscreen 1 +gfx_iRefreshRate 60 outdated GPU drivers
The following steps will help you bypass the error and get back to blasting aliens. 1. Edit the Configuration File Manually