My friend has an external hard drive that is formatted as NTFS but it can be read from and written to her macbook. She doesn't use any external software to do that, it just seems like her hard drive is compatible. I tried to connect my NTFS external hard drive to her macbook and it can only read from but not write to my hard drive. I'm just wondering if maybe there are several different types of NTFS that allows it to be written to from a mac? And also, what enables her NTFS hard drive to be written to from her macbook?