You need to DOWNLOAD the demo.
then UNPACK the zip file into a folder
Then run the .exe file
If the demo went poof you did something wrong
go to the topic i made about this a month ago and follow the link, there will be a page, click the link there, a pop up apears, right click on the link there and save target as
Haven`t checked the page since i posted it though, if you ran into further dificulties buzz me
Take care!