I lost my Parashara Light CD to download into my computer but I have the key that came with CD.
It's impossible to download the application because even the demo costs money. You will have to get in touch with the developer to solve this issue because it's the only way. The software appears to be on Commercial license, which means download is possible only if you have purchased it.
Contact us page: http://www.parashara.com/contact.html