<< Yup, Linux too. Of couse, the low level driver stuff and the kernel has hand optimized ASM built into it too. It really doesn't matter what language they used anyways, becase in the end x86 byte code is x86 byte code.
Very little of the kernel is ASM, and where it's used it's used out of necessity not for speed. It does matter because Linux isn't just an x86 OS, keeping away from x86 specific code and asm is pretty important. >>
I actually wasn't refering to Linux. The question was about Windows being created in C/C++. I added linux in as an FYI. Sorry for the confusion.