This troll is so old. Everyone knows Windows is written largely in C, with a bit of platform-specific code written in ASM. Some user-mode GUI stuff(parts of explorer, IE, similar crap) is written in C++, and some newer management stuff in C#. I can't recall anything in the core OS or base applications written in any BASIC variant, that's just stuff for the consumer. As for Turbo Pascal, ahaha, no, why would they use one of their old competitors language to write stuff in, especially a 16-bit DOS only, non-optimizing compiler. IHBT