After not playing FSX for a while, I started it up, everything seemed normal until I loaded up a free flight. First thing I noticed was that 7/8ths of the screen was black, with the other remaining 1/8th being my desktop (on the right). Also the loading bar was shifted to the left. When it finally loaded I could hear the engine, and could control the plane, but I just couldn't see anything on the screen. I could press escape and see the menu though. I need help!

Is that Windows8? Maybe a problem with a driver... did you attempt alt+enter to go into windowed?

This always happens to me in air hauler when I start fsx through air hauler. Im on win7. The solution for me was to just wait untill fsx has finished loading and you get the black screen (but can hear the sounds etc). Press pause, and alt + enter to go to window mode. Then you can alt + enter again to go back to a (working) full screen mode.

That said, FSX should never be started with other aircraft than default cessna 172 started. This will ensure correct operation of other addons.