Oldest GUI application that still runs on Windows 11

The application, CDPLAYER.EXE, dates back to Windows NT 3.1 build 347, an early prerelease version. According to developer Boris Popik, no older GUI application can run on Windows 11 because earlier builds hadn't finalized the PE format and calling convention.

Historical Significance

This discovery underscores Windows' exceptional backward compatibility, allowing decades-old software to function on modern systems. Popik also identified other potential contenders but chose not to disclose them, preserving an element of surprise for tech enthusiasts.