Unless it was the last plane you loaded, or it was the one that was loaded when you shut the program down, I wouldn't think it would be a plane you downloaded. If you know which one it was, you can remove it manually by deleting the files from the folder. The program only loads the plane and scenery it was using when it shut down last. If that doesn't work, you might try a system restore. I don't believe G3 can be loaded in safe mode, but you can try that too.