Actually, I don't think Macs can read NTFS. I do believe they read FAT32 however. Open Applications, go to your folder called "Utilities". Inside, look for disc utility, run that, and see if you can see the drive. If so it probably needs formatted. If not, close that, click the apple at the top left corner of your screen, then click "About This Mac". On the window that comes up, click "More Info". You will see a screen listing different devices and settings. On the left, look for usb(if it connects via usb), then click on that, see if it detects the drive attached to the machine or not.