Set up Media Center for the First time
From JRiverWiki
When you first install Media Center, you will be asked to Import Files. If you had a previous version of Media Center, your library will be converted to the Media Center 12 format, and a backup of your original files will be created in C:\Documents and Settings\[User Name]\Application Data\J River\Media Center [version]\. See Upgrading from a Previous Version.
