A Hitachi USB external hard drive is a device that acts as portable, removable storage for your personal computer. If you need additional space to house files on your computer but don't want to go to the trouble of installing an internal drive inside the case, a USB external hard drive is your best option. These drives are "plug and play" devices, which means that very little can actually go wrong. If you're having problems, fixing them shouldn't take more than a minute or two.
Check your connections. A USB cable needs to be connecting your Hitachi external hard drive to your computer. Your external hard drive's power cable also needs to be plugged into a functional wall outlet, surge protector, extension cord or power strip.
Make sure your Hitachi USB external hard drive is turned to "On." An "On/Off" button is present on the front of the unit. If the indicator light around said button is not illuminated, the drive is "Off" and your computer won't be able to recognise it. Press it to turn it on and then try to access your drive again.
Format your hard drive. If your Hitachi USB external hard drive doesn't currently have a file system on it, you won't be able to use it to store data. Open up the "Computer" icon in the "Start" menu. Right-click on your USB external hard drive's icon and click "Format." Click "Start." This will install a file system on your Hitachi USB external hard drive. After this process is finished, you will now be able to use your drive.
Restart your computer. Certain models of computers (especially older models) won't recognise new hardware unless your computer boots with the hardware already connected. Leave your USB drive plugged in and restart your computer. Once you do this, your Hitachi USB external hard drive should appear as normal in the "Computer" folder with all of your other drives.