I have a 300 GB external hard drive. Using Windows I made a 200 GB NTFS partition. My plan was to later make a 100 GB partition for Time Machine. I have been looking through disk utility, and I have not been able to figure out how to add a partition without erasing the whole drive. I have lots of things stored on the 200 GB NTFS partition, so I don't want to erase the whole drive. Does anyone know how to add a Mac partition without losing the NTFS one?