How and where do I order the Cdrom and is it available for Windows 10?
If you visit the official website, then you'll see that ARC500 for GRE PSR500 and PSR600 is available for Windows 10 and as a CDrom option that you can purchase for your needs. Kindly, access the link below to see all the option related to purchasing, downloading and system compatibility for this application.
Official website: http://www.butel.nl/products/arc500/arc500.html
Note: Click on the CDRom linked file to see all the possible buying options.