Problem:
./src/mongo/util/processinfo_win32.cpp

See

198     bool ProcessInfo::checkNumaEnabled() {
199         return false;
200     }

Appears that this check assumes that there is no NUMA impact for Windows.

Solution:
It appears that Windows supports APIs to find this info, see

http://msdn.microsoft.com/en-us/library/windows/desktop/aa363804(v=vs.85).aspx

Next Step:
Confirm if NUMA affects Windows in the same way as Linux (assumption is yes).