Microsoft CTO Says 30-Year-Old Win32 API Still Powers Windows 11 in 2026

Microsoft CTO Mark Russinovich has acknowledged that the Win32 API, which dates back to the mid-1990s, remains the foundation of Windows 11. He made the comments in a recent interview, noting that despite efforts to replace it, the old code persists.

Win32 API persists despite replacement attempts

Russinovich pointed out that Win32 has survived multiple attempts by Microsoft to reboot the Windows API surface, such as WinRT during the Windows 8 era. He described Win32 as a fundamental layer inside Windows that many apps and ecosystems have been built on, giving it staying power.

He highlighted that tools like Sysmon and ZoomIt, which were written in 1996, are now more relevant than ever in 2026. The CTO’s remarks underscore the enduring importance of legacy code in modern computing.

Tom’s Hardware reported the comments. Microsoft has not confirmed any plans to replace the Win32 API in future versions of Windows.