Intranet not working

I am trying to set up an intranet for our organization. I have a windows 2000 server and I installed IIS on it and I can FTP to the server but if I try the web browser I get a 404 error. The address is the same as the ftp but http. From a command line I can ping the name and I get a response. The name format is intranet.companyname.com
What could the problem be?