Okay, so I'm well known in my town for liking to tinker with computers/older electronics. Awhile back, someone gave me an old Windows XP machine for free. I took the machine and fiddled around with it for a while and then put it away. Recently, I've been cleaning my house and found the old computer. I looked through it and I have nothing of use for any of the components besides the hard drive. I'd like to use the drive for extra storage as I'm a photographer. However, to do this I'd need to remove the OS and unfortunately I don't have a Windows XP installation CD to remove the operating system off of it. How can I remove the OS and files on the drive?