My old computer had an AMD quad core CPU and VISTA-32. I upgraded to an AMD 8 core CPU and a clean install of Win 7-64 (FSX is not on C: drive), now some of my aircraft don't function. For example, the Acceleration F/A-18 original aircraft work correctly, but the addon squadrons do not. They show up in the preview window with only the nose gear extended, and when I start the flight, the aircraft is on the runway with a collapsed nose gear. I also have the Captain Sim two seat F/A-18D installed. That aircraft looks ok in the preview window, but when I start a flight it is on the runway with no landing gear (just hovering off the ground) and the flight controls don't operate (flaps don't move, stabilators don't move, ailerons don't move). Everything worked perfect on my old computer configuration.