The site being accessed is protected and you either entered the incorrect password or the host does not want users coming from your domain to enter. Some sites will only allow specific domains to access the site. For example, some U.S. government sites (with the .gov top-level domain name) will only permit users coming from .gov or .edu (educational sites) to gain access. Or some educational sites only allow access from other educational sites.
Solution If you are sure you have access to the site, try typing the password again. If you don't have a password or your domain does not have access to the site, you won't be able to access it.
401 Unauthorized Error message 
