You've all prob solved this problem for a thousand other folks... I cant access my Ext Hard Drive. It worked fine on my PC first time around. When I took it to my MAC it was read only. I reformatted the EHD so that I would be able to copy files from my MAC. Now I want to transfer some of the data back to my PC but I can no longer access the drive on my PC. I've read some threads with related issue. Drive shows up in Devices and Printers. Drive shows up in Disk Partitions> Create and Format Hard Disk Partitions> but when I right click on the drive, "Change Driver Letter and Paths" option is greyed out. Drive does not show up when I go to Start>diskpart>run as administrator>list volumes... I know the data is on the drive and my computer somewhat recognizes the drive. But I cannot access to explore, save to , etc. Please help.