Sysinternals is a suite of advanced system utilities and troubleshooting tools developed by Microsoft. It provides users with powerful tools to monitor, diagnose, and manage Windows operating systems. These tools help in understanding system internals, performance issues, and security vulnerabilities. The suite includes popular utilities like Process Explorer, Autoruns, and Process Monitor, which allow users to view running processes, manage startup programs, and track file system activity. Sysinternals is widely used by IT professionals and system administrators for effective system management and troubleshooting.