1. In Eclipse, find the Eclipse Console view (looks like below).
  2. If the console view is not showing then select Window -> Show View -> Console
  3. Select the arrow next to the little computer and select the server that is running from the drop-down menu
  4. Select the red square to stop the server
  5. Go to http://localhost:8888 and verify that the page no longer loads.Note: If a page is still showing then repeat the above steps for all of the servers listed in the drop-down menu next to the little computer in the console window. If that still doesn’t work, another application may be using the port so refer to Windows Http localhost port conflict
  6. To restart, just run the Google App Engine project again (Right click -> Run As ->Web Application)