add docs on new service.bat facility

docs/reference/setup.asciidoc

@@ -53,5 +53,7 @@ include::setup/configuration.asciidoc[]
 
 include::setup/as-a-service.asciidoc[]
 
+include::setup/as-a-service-win.asciidoc[]
+
 include::setup/dir-layout.asciidoc[]
 

docs/reference/setup/as-a-service-win.asciidoc

@@ -0,0 +1,62 @@
+[[setup-service-win]]
+== Running as a Service on Windows
+
+Windows users can configure Elasticsearch to run as a service to run in the background or start automatically 
+at startup without any user interaction.
+This can be achieved through `service.bat` script under `bin/` folder which allows one to install,
+remove, manage or configure the service and potentially start and stop the service, all from the command-line.
+
+[source,sh]
+--------------------------------------------------
+c:\elasticsearch-0.90.5\bin>service
+
+Usage: service.bat install|remove|start|stop|manager [SERVICE_ID]
+--------------------------------------------------
+
+The script requires one parameter (the command to execute) followed by an optional one indicating the service
+id (useful when installing multiple Elasticsearch services).
+
+The commands available are:
+
+[horizontal]
+`install`:: Install Elasticsearch as a service
+
+`remove`:: Remove the installed Elasticsearch service (and stop the service if started)
+
+`start`:: Start the Elasticsearch service (if installed)
+
+`stop`:: Stop the Elasticsearch service (if started)
+
+`manager`:: Start a GUI for managing the installed service
+
+Note that the environment configuration options available during the installation are copied and will be used during
+the service lifecycle. This means any changes made to them after the installation will not be picked up unless
+the service is reinstalled.
+
+Based on the architecture of the available JDK/JRE (set through `JAVA_HOME`), the appropriate 64-bit(x64) or 32-bit(x86)
+service will be installed. This information is made available during install:
+
+[source,sh]
+--------------------------------------------------
+c:\elasticsearch-0.90.5\bin>service install
+Installing service      :  "elasticsearch-service-x64"
+Using JAVA_HOME (64-bit):  "c:\jvm\jdk1.7"
+The service 'elasticsearch-service-x64' has been installed.
+--------------------------------------------------
+
+NOTE: While a JRE can be used for the Elasticsearch service, due to its use of a client VM (as oppose to a server JVM which
+offers better performance for long-running applications) its usage is discouraged and a warning will be issued.
+
+=== Customizing service settings
+
+There are two ways to customize the service settings:
+
+Manager GUI:: accessible through `manager` command, the GUI offers insight into the installed service including its status, startup type,
+JVM, start and stop settings among other things. Simply invoking `service.bat` from the command-line with the aforementioned option
+will open up the manager window:
+
+image::images/service-manager-win.png["Windows Service Manager GUI",align="center"]
+
+Customizing `service.bat`:: at its core, `service.bat` relies on http://commons.apache.org/proper/commons-daemon/[Apache Commons Daemon] project
+to install the services. For full flexibility such as customizing the user under which the service runs, one can modify the installation
+parameters to tweak all the parameters accordingly. Do note that this requires reinstalling the service for the new settings to be applied.