I have just upgraded the HHD on my MBP mid 2009 and installed a larger drive. The original has now been installed in an external enclosure. I have been trying to erase everything on this drive in Disk Utility, but every time I try to partition/erase it I get a window pop up asking me if "Do you want MBP HHD to backup with Time Machine". Can some knowledgeable please confirm how I can erase everything from this ex MBP drive so that I can use it to back up my new drive. Michael.