FSX Startup Issue

Sometimes when I start FSX, it comes up with an error message saying FSX cannot find all the files it needs to start and that the installation needs to be repaired or reinstalled. The program then immediately shuts down before displaying the splash screen. The strange thing is it doesn't do this all the time. About 50% of the time, it starts normally. I've found that after I wake up my computer from hibernation, it seems to do it. However, even with a fresh reboot, it still does it. I'll have to reboot the system one or two times to get it working again. Even completely erasing all FSX files and reinstalling it doesn't solve the problem. I've got FSX on its own drive, but this shouldn't make a difference since all my other games are on a separate drive as well from the main OS. System specs are in my sig.