Posted 05 June 2012 - 04:59 PM
More than likely this drive is in NTFS format your mac can read NTFS but not write to the partition. I would recomend you install Paragon NTFS for Mac® install it and change the drive that way.
Larry D. Lawrence II
MCSE, MCP,ACMT, ACTC
Dell, HP, Toshiba, Apple, Lenovo, and IBM Certified Technician