I get an error message says more or less that I must be the system administrator, and I am. I'm signed in with full administrative rights, but the message keeps coming up and the demo won't finish the installation.
my first guess would be a corrupt file. I would spruce up my computer after deleting the download and start over, making sure you are logged on as administrator when you download
I think that was a good guess. Instead of trying the file I downloaded to my computer, I opened the file download direct from the site instead of saving it to the computer...and it worked fine.