What is what language is windows written in?

Windows operating system is primarily written in C and C++. These languages are designed to be efficient and fast, which makes them ideal for an operating system. Additionally, Windows includes components written in other languages such as Assembly, C#, Visual Basic, and JavaScript, as well as various scripting languages like PowerShell and batch files. These components are designed to handle specific tasks such as user interface design, database management, or network programming. Overall, the Windows codebase is massive, with millions of lines of code written by thousands of developers over several decades.