External hard drives can be a simple way to move a large number of files from one computer to another without making a lot of CDs or using multiple flash drives. Two computers in your house can share the same external drive. If you have a large budget, you can buy an external portable drive that plugs into your router, but if you already have a portable external drive you want to use you can link both computers to it by sharing the drive.
Connect the external hard drive to either one of the computers. Usually a USB cable connects the drive. Plug the cable into an available USB port on your computer and plug the drive into a power socket.
Share the drive by going into Windows Explorer and right clicking on the drive. Choose "Properties," then choose the "Sharing" tab. Click the check boxes "Share this folder on the network" and "Allow network users to change my files."
Put each computer on the same network. You must have a home network. If you don't have one, you need to buy a router and connect each computer to it. In the "Control Panel" choose "System." Click on the "Computer Name" tab, then click "Change." Type in a name in the "Workgroup" space and make sure it is exactly the same on each computer. Restart the computer. You can now see the external drive on the original computer and on the second computer under the network drives.
Make the external drive a regular drive on the second computer. Go into Windows Explorer and click on the "Tools" menu. Choose "Map network drive." Pick a drive letter to use in the drop down box and click browse to find the external drive on the network. Look under the workgroup and look for and select the drive. Select the "Reconnect at login" box and click "Finish." The external drive will now appear like a regular drive on both computers.