So, if you are unable to copy files to your external hard disk or USB stick, the problem is that you're dealing with an NTFS-formatted drive. As you probably know, external drives come pre-formatted using the NTFS file system, which Mac OS X can successfully read, but cannot write on.
Transferring files from your Mac desktop to a USB flash drive or an external hard disk seems to be a simple task, right? Well, that might not be as easy as you think, especially if you are more familiar with Windows. How to transfer files from a Mac desktop to an external hard drive
