Fix ProcessTree test issue on Windows by skipping System Idle and System processes

core/src/main/java/hudson/util/ProcessTree.java

@@ -395,6 +395,7 @@ public abstract class ProcessTree implements Iterable<OSProcess>, IProcessTree,
         Windows() {
             for (final WinProcess p : WinProcess.all()) {
                 int pid = p.getPid();
+                if(pid == 0 || pid == 4) continue; // skip the System Idle and System processes
                 super.processes.put(pid,new OSProcess(pid) {
                     private EnvVars env;
                     private List<String> args;
@@ -1227,4 +1228,4 @@ public abstract class ProcessTree implements Iterable<OSProcess>, IProcessTree,
      */
     public static boolean enabled = !Boolean.getBoolean(ProcessTreeKiller.class.getName()+".disable")
                                  && !Boolean.getBoolean(ProcessTree.class.getName()+".disable");
-}
\ No newline at end of file
+}