там написано
When building Apache, you must choose an MPM to use. There are platform-specific MPMs for some platforms: beos, mpm_netware, mpmt_os2, and mpm_winnt. For general Unix-type systems, there are several MPMs from which to choose. The choice of MPM can affect the speed and scalability of the httpd:
Те для винды всего один плагин: mpm_winnt
Который в свою очередь и так multithread
http://httpd.apache.org/docs/2.4/mod/mpm_winnt.html It uses a single control process which launches a single child process which in turn creates threads to handle requests
