Setting up FTP

I setup IIS and forwarded the port and IP to my comp in my linksys router, I put some files in the ftproot and I can reach the ftp server from outside my intranet, but I can’t open up the files in internet explorer, I get a “Page cannot be displayed”, they are just simple text files. The only way I can see the files is to select “copy to folder”, go to that folder and open it up. Why can’t I open the files in IE? I went to ftp.microsoft.com and they have text files there that I can open up in my browser.
Can’t figure out why it won’t open on my site. Any help is greatly appreciated.

Thanks,
Kevin