Can anyone think of a way to protect a download link so that people cannot see where the download is coming from? We think that people are using a direct link to download our software. (thus bypassing the registration page) We would like to change the link and add some more protection. We have a IIS 5 box.

I have already looked at some protection through a third party (anti-leech.com) but want to keep my options open if anyone has any ideas.

Thanks in advance.