A Mac is completely different from any other computer. It has an operating system (Mac OS) which differs radically from Windows or Linux or any other operating system desktop.
The differences that we could list are endless, but the one that interests us (to organize a Hard Drive on Mac) relates to the reading system. On Windows (NTFS formatting applied to most USB devices and DVD used by Windows) on a Mac, this type of formatting is not supported, then the external device, and you cannot change (but you read it).
1.) Now if you own a device used on Windows and want to use it on Mac (or both) saved its contents to another hard disk or on your computer. Then connect it to your Mac, open the Launchpad (or if you have a previous version too open Finder > Applications ) and run the Disk Utility application. If you do not find installed when you purchase your Mac, then I suggest you download Tuxera (a very similar, and many other features). Once launched one of the two selected applications the device to format and forward the option initializes.
2.) On Name: Enter the name you want to give to the device, Format: Select the format to use. If you need to use it on Windows, NTFS put, if you want to use it on both Windows and Mac, then choose the FAT32 format.
3.) Now press Erase. Begin the process, first make sure you have a copy of the files on the device as they will be completely erased! After a few minutes (even seconds if you do not have a whole hard disk), the process will be completed, and the device is fully usable on both Mac and Windows. Now you can re-transfer the copied files inside of it. You can use it as a partition for Time Machine partition to BootChamp, such as USB drives. So thanks to this feature of Disk Utility (or Tuxera), you can take full advantage of all the features of your Mac or Windows. You cannot use the internal hard disk of your computer (transferring your files to the newly formatted) making it faster and more responsive to your PC, where there will be room for a greater number of applications and software ..