OK, Thank you. I can't test this for a few more days because I'm away right now from my computer. I will install a blank demo, and I'm sure it will do a lot better (because I did the same thing last year, installed blank demo, and it worked very good). The only problem is, how do I put back my custom scenery and addons? I don't want to fly with the default X-plane engine. But putting them in one by one would take up SO much time. What's your advice on what to do after I've installed a blank demo