If you just built a PC, or added a brand new hard drive or SSD to an existing computer, you have to format it before you can actually store data on it. This is called 'initializing' the drive.

You might need to format an external hard drive before you can use it with your computer. We have some tips to help the process go smoothly.

While the Mac can use a hard drive formatted for Windows, some features may be limited. So it's a good idea to format a new hard drive specifically for macOS.