Microsoft Knowledge Base Article 178631 contains the following summary:

The Microsoft Distributed File System (Dfs) can be used to simulate NetWare's MAP ROOT utility, allowing users to map a drive letter to a directory that is not itself shared. This is especially useful for mapping to users' home directories without creating individual shares.

Here is an example:

  1. Create a folder called Homedirs on the server.
  2. Create user folders beneath Homedirs.
  3. Install Microsoft Dfs and set Homedirs as the root for the Dfs. Consult the Readme.doc for detailed instructions for setting up the Dfs.
  4. Restart.
Users will now be able to map a map directly to any folder within the Dfs. For example, if a folder named User1 has been created beneath Homedirs, the following command is valid:

net use u: \\DFSServer\Homedirs\User1

Drive U will be mapped to User1, even though Homedirs is the share point. This format is also acceptable when mapping drives from within Explorer.