Photoshop 7 is a very old product and may not run on modern operating systems. I can't recall but if it needed activation then that would now be impossible as the activation server has been shut down for these old versions of the program. One thing you can look at is downloading Photoshop CS2- a Special version
Download Acrobat 7 and CS2 products
I cannot confirm that you can legally qualify for the upgrade -you'll need to read the web page yourself and decide on that, but that would solve your problem.
Terri