Just to add that I have changed two instances of 'DS' to '/' within the easyfolderlistingpro.php file and it still does not work. The URL that is being produced looks like:
http://localhost/documents%5CMedical_Students%5CFeedback/Feedback.pdf
Where the file is stored at: C:wampwwwdocumentsMedical_StudentsFeedback.pdf
The error being produced is: The requested URL /documentsMedical_StudentsFeedback/Feedback.pdf was not found on this server.