The file system on the cloned MD600 HDs will most likely be a Linux variant (ext3 or ext4 I'm guessing). Windows cannot mount that type of file system without some tricks. One approach might be to run a Linux virtual machine in VirtualBox or similar and try to access the HD that way.

Soundserge

Antipodes CX + Roon, 818v3, DSP 7200SEs, 218, DSP3200s