I still use FS2002 quite a lot, mostly because of all the airplanes I installed and personalized within the year or two after it was introduced. I also use FS2004 and FSX-SP2 on the same PC. Old AthlonXP processor, Windows XP. Decent frame rates on all the sims, best on FS2002. I published a few gps-related gauges coded in C a few years ago if anyone is interested. Search "Dibbell" in FS2002 panels. I also still have a working installation of FS2000. The tinkerer in me keeps me from letting the older versions go.