shims

Microsoft's Windows operating system has developed intricate compatibility mechanisms over decades to ensure that older games can run on modern machines. It maintains compatibility databases that recognize software with known issues and applies specific fixes, known as shims, which adjust the OS's responses to meet the game's expectations without modifying the game's executable. Users can also manually apply fixes through Compatibility settings, allowing them to emulate earlier operating system behaviors and address specific issues. The compatibility shims can modify interactions with APIs, file handling, system privileges, and display scaling. Microsoft provides AppHelp warnings for applications with known compatibility issues and maintains a comprehensive compatibility database located at C:WindowsAppPatch. Users can access this database and explore compatibility settings using the Windows ADK and the Compatibility Administrator tool.