After installation when called for roscore following message received (win10)

edit

straight dump of the terminal:

C:\Windows\System32>c:\opt\ros\melodic\x64\setup.bat

C:\Windows\System32>roscore
Traceback (most recent call last):
  File "C:\opt\ros\melodic\x64\bin\roscore", line 36, in <module>
    from rosmaster.master_api import NUM_WORKERS
  File "C:\opt\ros\melodic\x64\lib\site-packages\rosmaster\__init__.py", line 35, in <module>
    from .main import rosmaster_main
  File "C:\opt\ros\melodic\x64\lib\site-packages\rosmaster\main.py", line 43, in <module>
    import rosmaster.master
  File "C:\opt\ros\melodic\x64\lib\site-packages\rosmaster\master.py", line 47, in <module>
    import rosmaster.master_api
  File "C:\opt\ros\melodic\x64\lib\site-packages\rosmaster\master_api.py", line 72, in <module>
    from rosmaster.util import xmlrpcapi
  File "C:\opt\ros\melodic\x64\lib\site-packages\rosmaster\util.py", line 48, in <module>
    from defusedxml.xmlrpc import monkey_patch
ImportError: No module named defusedxml.xmlrpc