A Windows service is just a binary so figure out the binary
corresponding to the service and execute it like any other command.

Look here
http://forum.java.sun.com/thread.jspa?threadID=208036&messageID=707019
to see the Java method used.

Most services should be started upon the machine booting up and if they
are not started automatically the Computer Management snap-in can be
used to start them. Is there something your app is providing that can't
already be done through the default Windows tools?