Update check_ready_to_run in windows local mode (#1025)

* Update mnist-hyperband.test.yml

* Fix system node

* Fix pgrep in windows

tools/nni_gpu_tool/gpu_metrics_collector.py

@@ -25,9 +25,14 @@ import time
 from xml.dom import minidom
 
 def check_ready_to_run():
-    #TODO check process in windows
     if sys.platform == 'win32':
-        return True
+        pgrep_output = subprocess.check_output('wmic process where "CommandLine like \'%nni_gpu_tool.gpu_metrics_collector%\' and name like \'%python%\'" get processId')
+        pidList = pgrep_output.decode("utf-8").strip().split()
+        pidList.pop(0) # remove the key word 'ProcessId'
+        pidList = list(map(int, pidList))
+        pidList.remove(os.getpid())
+        return len(pidList) == 0
+    else:
         pgrep_output =subprocess.check_output('pgrep -fx \'python3 -m nni_gpu_tool.gpu_metrics_collector\'', shell=True)
         pidList = []
         for pid in pgrep_output.splitlines():