I'll try to make a very long story short. My PC had the latest Garmin Trainer and the latest XP installed. I then installed the Reality XP GTN 750 and it loaded, except there was no database. Scouring through the install manual, I played around with environment variables and removed and reinstalled the Garmin Trainer - twice. Although the GTN 750 comes up, its screen is blank. I'm not sure what to do next. I have removed all environment variable that I had added. I have also found that the manual refers to folders that do not exist.