Can't unmount disk
I am trying to erase to reuse a 750G external harddrive and despite selecting the drive media name in Disk Utility and the Drive's name, it won't erase. Says Can't unmount disk.
I have Verified the disk [both the media name and the indented drive's name] and also tried to Partition it but still get the same message - it says it has a GUID Partition Table, it has Read/Write status, I checked Get Info and I have Read-Write privileges.
Is this a Dead Drive?? Or is there any other way to erase it???
Mac Pro, Mac OS X (10.7.5), 17G RAM