About protecting directories
You can limit access to files stored on your site by requiring users to type a password to gain access. This is known as "protecting directories."
When users attempt to access a file in a protected directory, the Web server displays a login window. Users with access privileges enter their user names and passwords to access the file. Users without access privileges cannot access the file.
You protect directories in one of two ways:
Through the Site Administrator control panel if Microsoft® FrontPage® Extensions are not enabled for your site.
Through the FrontPage Extensions interface if FrontPage Extensions are enabled for your site.
Note: To determine whether FrontPage extensions are enabled for your site, click Site Information on the System Menu, then check whether FrontPage is shown as available in the Services and Options section of the Configuration window.