On Windows, check the Processes tab in Task Manager. Look for any remaining Harvest-related processes (rtserver.exe, hserver.exe, bkrd.exe, agntd.exe) and kill those.
On Linux and Unix, execute "ps -ef | grep <process name>" to look for any remaining Harvest-related processes (rtserver, hserver, bkrd, agntd). Kill any remaining processes that you find.
Be sure to search for and kill the rtserver process as a last step. If you kill the rtserver process while the broker is still running, the broker will try to initiate a new rtserver process.