I use FSUIPC to run a program called heliforce it makes the helicopter in FSX operate more realistically like a real helicopter , just before deleting FSUIPC from the FSX module folder I flew the helicopter with heliforce - FSUIPC so I knew it was working ok . I then deleted older version of FSUIPC from the module folder and installed the latest version . Then right after that I ran FSX and that's when i noticed the black blank screen problem with only the jet ranger and robinson helicopters . Deleting FSUIPC is the only thing i did before i had the problem, but maybe as you stated i inadvertently removed or corrupted some thing i shouldn't have . thought i was only in the module folder and it only had files titled FSUIPC . just for trouble shooting to see what would happen i did the same thing on another computer with FSX , heliforce and FSUIPC and no problems . thanks for your response, if you have any suggestion please let me know , I read some place that if the FSX configuration files is deleted FSX will regenerate a new one, so i was thinking about trying that but note sure . Is some way to check for removed or corrupted files , thanks for your help