This comprehensive security report investigates unpatchable vulnerabilities in Windows 10 and11, focusing on systemic flaws that resist traditional patching due to their deep integration intothe operating system’s architecture, hardware dependencies, and legacy compatibility requirements. These vulnerabilities, rooted in fundamental design choices and ecosystem constraints,pose significant challenges to securing millions of Windows devices worldwide. The report examines three critical vulnerabilities: legacy BIOS/UEFI firmware weaknesses, kernel memorymanagement flaws, and backward compatibility with legacy protocols. It provides a detailedtechnical analysis, exploitation vectors, detection challenges, and comprehensive mitigationstrategies. With Windows 10 approaching its end-of-support deadline in October 2025, theseflaws pose heightened risks, necessitating proactive defenses. This report adheres to responsible disclosure principles and aims to support Microsoft’s efforts to strengthen Windows securityin 2025