A roaming user profile is user data, stored in a specific folder structure, to follow users as they log on to and log off from different computers. Roaming user profiles are stored on a central server location. At log on, Windows copies the user profile from the central location to the local computer. When the user logs off, Windows copies changed user profile data from the client computer to the central storage location. This ensures that the client data follows users as they roam the environment.
Roaming user profiles solve part of the roaming problem, but it created added concerns. User profiles can increase in size, some as large as 20 megabytes or more. This increase causes delays in user logons, because it takes some time for Windows to copy the information to the local computer. Another concern with roaming user profiles is that they are saved only at logoff. Therefore, when a user logs on to one computer and changes data within their profile, the changes remain local and remain local until the user logs off, making real-time access to user data challenging in a roaming user environment. Folder Redirection reduces some of these problems.