I want to share one external drive with both my PC and Mac. I do not want to share the data. I want to use the PC partition to backup my Vista OS and want to use the Mac partition to backup my Mac OS. what is the best way to configure this? I had created an NTFS partition using my Vista machine, but when I plugged in the external drive into my Mac and tried to create a Mac OS Extended partition, I lost my NTFS partion. I dont know what I am doing. Help Please!!!!