How to format a hard drive for use on a PC or Mac computer

To format a hard drive before you start using it in Windows, use the Disk Management utility; on a Mac, use Disk Utility.
Ars Technica

Creating System Disk using DOS, trying to reformat hard drive

I'm trying to reformat my hard drive (only have one) and it won't let me b/c the os is on the hard drive. I tried creating a start-up disk with Windows XP so that I could boot to DOS and format from a ...