The FSE program, (‘FSE client’ or 'FSE Agent') is what bridges your Flight Simulator with the FSE website and database. When you start up the program, it will take a few seconds to ‘locate’ your open MSFS. Look in the lower left corner of the program window for “FS Connected”. Once you see that, you are ready to start a flight. If it shows "FS not linked", either your FS9 / FS2k2 is not open or there is a communications error between the two. Be sure FSUIPC is installed properly and try again.
In the lower status bar there is some more important information. To the bottom right is the rental time counter that starts with your flight and indicates you how long you have until the rental is over. IMPORTANT! Make sure you land before the counter reaches zero or your flight will be cancelled. You do not need to land at your final destination -- simply ending your flight (by landing and shutting off your engines) and restarting your flight will start your rental time over. The status bar window to the left of the counter shows you the registration of the aircraft you are flying.