Hi gerri,
I am not with Laminar Research; just a flight simmer.
Further to what Thomson (Laminar Research) has advised I would suggest you perform a "fast" digital download onto a portable hard drive or disc drive ( 1TB capacity) and then copy onto the computer you plan to run X-Plane from. If you backup to DVDs you will need somewhere in the order of 10 discs.
When you do copy onto your "home" computer install onto the desktop or a dedicated drive for clean operation. In the installation process X-plane operates in a clean environment whereby it does not mix or retain files in other software packages eg operating system.
If you download to a portable drive you will be able to copy quite easy to your home computer and you will also have your backup as a substitute for creating a DVD backup system.
Be aware of a few issues. Firstly when you run the digital download version I have read you have to be connected to the internet at all times for it to work. Secondly, there will be updates from time to time and they will download to your home computer. Don't select Beta updates unless you are an experienced "tester". Thirdly, when an update occurs you will then have to backup onto your portable drive to maintain the integrity of your version.
Hope this helps.
Glenn