This site is being deprecated.
Please see the official X‑Plane Support page for help.
You can read more about "Installing the X-Plane 10 Digital Download" here. More info aboud downloading older versions you can find here.
If you can run X-Plane 10 Demo on your computer, then there shouldn't be any problem with full version of X-Plane 10. You can download the free X-Plane 10 Demo and try.
This site is no longer being actively maintained.