It is a known issue that the NetPerfMon service won't stop in a timely manner. Right after the install and during what is called the "Configuration Wizard", you'll see a message that it is trying to stop the NetPerfMon service. Open up the Windows Task Mananger, find the 'NetPerfMonService.EXE' process, right click on it, and hit "End Process". I've confirmed with an Orion team lead that this is safe to do. The Configuration Wizard should then continue and will restart the NetPerfMon service automatically when it is finished.