Installing a new hard disk is not only a great way to extend the life of a computer that is running out of storage space, it’s easy to do.
To install an external hard disk, all you have to do is plug it in to your computer and connect the power cord. Most hard disks plug into a USB port, but some plug into a FireWire or iLink port (sometimes known as "IEEE 1394"). Be sure your computer has the right kind of port as the external hard disk to want to add. For additional instructions, check the information that came with your external hard disk. You may also want to install any software that came with the hard disk.
I want to add also that an external hard disk cannot function as your primary hard disk where you install Windows, but you can use it as a secondary disk to store programs and files. This is a good way to create plenty of extra space to store digital photos, videos, music, and other files that require a large amount of disk space.