try:
In Windows, start regedit, go to HKEY_Local_Machine, Software, Oracle and add entry NLS_TIMESTAMP = 'YYYY-MM-DD HH24:MI:SS'
alter session set NLS_TIMESTAMP_FORMAT='yyyy-mm-dd hh24:mi:ss.ff';
try:
In Windows, start regedit, go to HKEY_Local_Machine, Software, Oracle and add entry NLS_TIMESTAMP = 'YYYY-MM-DD HH24:MI:SS'
alter session set NLS_TIMESTAMP_FORMAT='yyyy-mm-dd hh24:mi:ss.ff';