How do I download Photoshop for windows xp and vista.... I currently pay per month for photoshop and a computer running vista i ned to install photoshop on two aditional machines. How can I download, photoshop says I have an os that is no longer supp

I have a computer running windows vista that I pay per month for photoshop, I want to use photoshop on two other computers I have, not that it matters but they are both identical hardware wise, and software one runs xp and the other runs vista, I can upgrade but I am not intrested in other os. When I attempt to download I am told that my os is no longer supported. Now i know that I could find an offline version and should be able to get it installed but im not sure of a safe site that provides the iso or install exe. I want to use the other two computers because they have touch interface early computer/tablet highbird. thanks in advance.