From the "bin" folder of your Apache install folder run the command:
apache -k install -n "MyServiceName" -f "c:\YourPathTo\httpd.conf"

If you skip -n "MyServiceName" it will default to Apache2.
If you skip -f "c:\YourPathTo\http.conf" it will default to "conf\httpd.conf", relative to were apache.exe (or httpd.exe) is located.

Test the service's configuration file:
apache -n "MyServiceName" -t

Test your new Apache server at:
http://127.0.0.1/index.html (you should see: "It works!").

Uninstall:
apache -k uninstall -n "MyServiceName"

You can run multiple installation of Apache on the same server using different service names.
For help with the full install process: Apache Install on Windows: Overview

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Check this nice feature of Apache 2.2.x: Graceful restart of Apache

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Ref: http://httpd.apache.org/docs/2.2/platform/windows.html