Thank you. now I have a Mac and a Windows how do I download to both systems?
Since you are talking about two different computer operating systems and online download purchase of a serial number, you should consider contacting Adobe Chat about the matter to avoid any confusion.
To do that, please use the following link and then click on "I need more help" to bring up the Adobe Chat pop up.
Please let us know the outcome.
Also, be aware that the "idea" is one person with a desktop and a laptop for travel... NOT 2 computers being used at the same time