Included with the CD's are several books of manuals, one of which is all about installation. (though they're only moderately helpful. A made up example: "To enable Reverse Polish Notation, click "yes" when asked "Do you want to enable RPN?" So now you wonder "What is RPN, what is it used for, why do I want it, what is its downside, and what do I lose if you don't enable it." But neither the manual nor the documentation explain it.)
[For the curious, RPN is a real concept, but it is used on engineering calculators and has absolutely nothing to do with Maximizer.]
I have never the downloaded software. Maybe if you have the original downloaded files you could try burning them to a CD.
Otherwise, common sense would say to try to recreate the steps you used when you originally downloaded and installed on your old computer on the new one.