Watch this video and then follow the steps below.
Once you see the No-IP Dyanmic Updater:
1. Click on the No-IP DUC menu.
2. Click on Preferences.
Enter the username and password that you created on the no-ip website earlier.
3. Click on the Hosts tab.
4. Check off the host you want to use.
5. Click on the Daemon tab.
6. Click on Start.
7. Click on Launch Daemon at System Startup.
8. Close and quit the application.