From page 7 of the supplied Mede8er 'Quick Start Guide':
The MED500X has a built in Hard Drive format feature that formats the hard drive with a main NTFS partition and other small internal partitions for propriety use.
The Hard Drive should be formatted in the Mede8er MED500X to ensure full functionality. A pre formatted Hard Drive can be used but you may not be able to use all the internal features of the MED500X.
To Format the internal Hard Drive select SETUP menu and then HDD Format.