What was Microsoft windows (later versions) written in?

[crossroads]

Was it c/++ or was it faithful to dos or was it assembly code, python etc.

[fo3nix]

Lots of it is still in C, with other stuff in C++. From what I understand anyway; I don't work at Microsoft so don't have access to the source code.

I'm sure now they've started using C# or similar, but probably only for some uses.

Much of the code is pretty old (possibly with the exception of Vista, with much of the underlying code being rewritten to add DRM-like functions).

py etc. is too high level. Assembly is too hard to program fast (and C can basically just be translated into assembly equivalent by the compiler). What do you mean by dos?

Worth noting too perhaps is that they don't use their commercial build tools, i.e., Visual Studio, they use their own custom tools.

[heathfield]

Microsoft jealously guard their source code, and only release it to universities and government agencies on strict condition that it will not be revealed to anyone else.
Incomplete portions of their code have been leaked and posted on the internet.

[crossroads]

I had an idea they were using mainly c and C+.
Thanks for your help, its shed some light on my problem.

[crossroads]

its OK, i found an article on microsofts website and i might apply for a licence.
Cheers, [:)]
http://www.microsoft.com/resources/sharedsourc e/licensingbasics/sharedsourcelicenses.mspx

[tubeway]

note to fo3nix - dos - is disc operating system, which is what we had before windows.

[rojash]

tubeway, I'm certain that fo3nix knows what DOS is - I imagine he was wondering how you could write an operating system (or any other program) using only an operating system :-)

[fo3nix]

rojash: exactly.