It seems like you're encountering an issue running Quake II on OpenGL mode. Here are a few steps you can take to troubleshoot this problem: 1. Update Graphics Drivers: - Ensure that your graphics card drivers are up to date. Outdated drivers can sometimes cause compatibility issues with OpenGL. 2. Compatibility Mode: - Try running Quake II in compatibility mode. Right-click on the game's shortcut or executable, go to Properties, and then the Compatibility tab. Try running it in compatibility mode for an older version of Windows. 3. Run as Administrator: - Right-click on the game's executable and select "Run as Administrator." Sometimes, running programs with elevated privileges can resolve issues. 4. Disable...