This site is being deprecated.
Please see the official X‑Plane Support page for help.
Have a look at he following link at http://www.x-plane.com/kb/x-plane-digital-download-xdd/ You will need to scroll down (read) the page to find all of the answers.
Hope this helps.
There is no upgrade to X-Plane 10 or 11.You can buy X-Plane 10 Digital Download here or DVD here. You can also buy X-Plane 11 Digital Download here.
This site is no longer being actively maintained.