"Presumably much like Linux everywhere works"
Indeed it does!
"except Windows has the slight advantage of being entirely modular in design from the ground up versus the more monolithic approach of Linux."
This is an irrelevant (and debatable; see above) detail regarding the kernel itself. If it were significant then I'd be seeing Windows on things like my ADSL router instead Linux.
What is significant is that most popular operating systems built around the Linux kernel are entirely modular and built from the ground up using packages (e.g. RPM, Debian). This provides a level of modularity that Windows could only ever dream of and it makes software installation and patching a breeze.