Microsoft CTO confesses that 30-year-old code from the mid-90s still forms the bedrock of Windows 11 — ancient Win32 API still the backbone, but CTO says it's 'more relevant than ever in 2026'

Source: Tom’s Hardware

Image credit: Microsoft

Win32’s Enduring Role in Windows 11

A top Microsoft executive, Azure Chief Technical Officer Mark Russinovich, has confirmed that Windows 11 still relies on a substantial amount of code written in the mid‑1990s. While the admission may surprise some, the deep roots of the Win32 API—and the massive ecosystem built on top of it—give it serious staying power.

“Legacy can still mean essential.” – Mark Russinovich (May 6 2026)
SysInternals site

Russinovich notes that those of us who were part of the computer scene in the 90s “were thinking flying cars and moon stations by the year 2026, not Win32.” The CTO’s candid confession underscores that Microsoft is aware of the legacy issues in its OS while still leveraging the same foundational layer.

Why Win32 Still Matters

• Fundamental Layer: “One of the reasons it’s got this staying power is just a fundamental layer inside of Windows that so many apps have built on,” Russinovich explains.
• Ecosystem Dependence: Countless technologies and ecosystems have been built on top of Win32, making it a de‑facto bedrock for Windows development.
• Failed Replacements: Attempts to “reboot” the Windows API surface—such as the introduction of WinRT during the Windows 8 era—did not achieve the expected adoption, reinforcing Win32’s relevance.

Microsoft’s Current Focus

The company is undergoing a major transformation aimed at improving:

• Performance, overhead, and reliability – see the recent initiative on Windows 11 performance improvements.
• Future OS direction: Last November, Microsoft executives boasted about Windows “evolving into an agentic OS,” a claim that sparked backlash and highlighted the tension between legacy support and new ambitions.

Despite these shifts, Win32 is not portrayed as “bad” by the CTO; rather, it is recognized as a stable, well‑understood foundation that continues to serve modern workloads.

Tools Built on Win32

Russell also highlighted that classic Sysinternals tools such as Sysmon and ZoomIt—originally written in 1996—remain “more relevant than ever in 2026.” These utilities are now integrated into:

• Windows 11 (e.g., Sysmon)
• PowerToys (e.g., ZoomIt) – see the latest updates on the PowerToys page.

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