code: @Extension
      public static WindowsInstallerLink registerIfApplicable() {
          if(!Functions.isWindows())
              return null; // this is a Windows only feature
  
          if(Lifecycle.get() instanceof WindowsServiceLifecycle)
              return null; // already installed as Windows service
  
          // this system property is set by the launcher when we run "java -jar jenkins.war"
          // and this is how we know where is jenkins.war.
          String war = SystemProperties.getString("executable-war");
          if(war!=null && new File(war).exists()) {
              WindowsInstallerLink link = new WindowsInstallerLink(new File(war));
  
              // TODO possibly now unused (JNLP installation mode is long gone):
              if(SystemProperties.getString(WindowsInstallerLink.class.getName()+".prominent")!=null)
                  Jenkins.getInstance().getActions().add(link);
  
              return link;
          }
  
          return null;
      }
docs: Decide if {@link WindowsInstallerLink} should show up in UI, and if so, register it.