I am attempting to install DDSPF20 on my new laptop.
My understanding of the best way to achieve this is to download the demo file of DDSPF20, then run it and enter in my key, which will then convert the game into the full version. Is this correct? If not, please tell me the best/proper way to perform a full install of DDSPF20 on a new computer.

In any case, after download the file for the demo, when I try to run the install file i get this error-

"This app can't run on your pc.
To find a version for your PC check with the software publisher."


Any help?

Yea, you should be able to download the latest version from viewtopic.php?f=303&t=30264

You may need to run the installer as administrator, or unblock it as some downloaded .exe files get blocked by windows for safety.