[monochromatic]

That’s a little surprising. I would have figured that outside the kernel/drivers, it’d be all C++.

[pickle-wizard]

There is a book about the development of Windows NT called show stopper. In the book they talk about this. C++ was pretty new in 1989 so Dave Cutler decided to stay with C to reduce risk.

Except for the graphics team, as they were managed by someone else. They decided to go with C++, and they were pretty much always late because everyone was learning and building the tooling around C++.

[solarkraft]

I'd have expected much more to be in C#.

[shaklee3]

There's no reason to write OS components in a language that will inherently give you a performance hit before you do any real work.

[maxxxxx]

From what I know for a long the OS division who writes Windows has been at war with the developer division who writes .NET and refused to use .NET. I think it has gotten a bit better recently.

[fffrantz]

Second this. Though Microsoft has been really busy getting their C++ sorted out lately. Funnily enough, C# performance has also seen some dramatic performance increase.