Hard drive format for mac!!!

I got the external hard drive that want to use in my Mac and i know that we need to format if we want to copy file in.

My problem is i want to back up my data into my old hard drive but i don't want to format it cause the data inside is really huge.

did anyone know how to use it for format without erase data contain inside the hard drive ?

plz help ;D

Well, if it has data on it, you certainly don't want to format it.

My guess is that it's formatted NTFS (for Windows) and that you can only read from it - but you also want to write to it.

If that's true, and moving the data off to another computer is not an option, then I would recommend getting an NTFS driver for the Mac that allows for Write operations. For this purpose, I recommend Paragon NTFS for Mac.