Log Reader is used to read specific MDF file. Once this file is selected via "Select Backup Files" pane of wizard, following error occurs:
"This file is in use. Enter a new name or close file that's open in another program"
OR
"The process cannot access this file..."
Log Reader will automatically read MDF/LDF files of database so there is no need to select this file manually in wizard. Simply hit Next on this pane to continue. The Select Backup files pane is only used to add BAK files.