A. Dfs is available for download from Microsoft http://www.microsoft.com/ntserver/nts/downloads/winfeatures/NTSDistrFile/default.asp. Follow the instructions at the site and fill in the form about your site. The file you want for the I386 platform is dfs-v41-i386.exe.
Once downloaded just double click on the file, and agree to the license. It will then install files to your drive which you need to install.
Windows 2000 has Dfs built-in as a core component.