Explanation of the ShellNoRoam Registry Area

HKCU\Software\Microsoft\Windows\ShellNoRoam

This registry area is used to store information on window position/size and view settings.
Windows allow for each folder to have unique view settings (eg. Details view) and this information is stored under the BAGS and BAGSMRU Keys.

The default value is set to %computername% of the machine on which the explorer.exe resides.
So in a terminal server environment it will be the name of the server delivering explorer.exe

The %computername% value is stored so that it can be used to detect if the folder view settings are applicable on this computer. This design is to ensure the folder view setting are only seen when the user is logged onto the same workstation as they made the view settings.
This design does not work in a terminal server environment where users roam around a pool of servers.

I gained this information from a very good article on the subject :
http://blogs.sepago.de/nicholas/2009/02/17/preserving-windows-explorer-folder-views-in-roaming-profiles/comment-page-1/#comment-4218