In pre-Vista versions of Windows, you could use the xcopy command to copy all user profile folders and their contents to another location, for example when you want to back up or clone the contents of a user's profile. This won't work in Vista or later however because xcopy doesn't handle directory junctions points properly. These directory junction points automatically redirects attempts to access legacy profile paths to their new profile locations. For instance, if you type dir /AL at a command prompt whose current directory is the root of C: drive, you'll see that there is a directory junction point named Documents and Settings present that redirects to the new location C:\Users where user profiles are now stored in Vista and later.
So what can you do if you need to copy user profile folders and their contents in Vista? Use the robocopy command instead, where you can include the /XJD switch that causes directory junction points to be ignored during the copy process.