• Start your computer up as normal, but make sure the external hard drive is attached.
• The best program available to try and recover data is PC inspector, which can be found on their main website through this link: http://www.pcinspector.de/default.htm?language=1. But you will need to select a different option depending on what you wish to do. If you deleted a file on your external hard drive that you know want back, pick the option "recover deleted files". If your system crashed, leading to damaged data, if you cannot access your drive or if you cannot find your drive's letter then select "find lost data".
• When you have done this, pick the hard drive that has the lost data, this will either be the logical or physical hard drive. The logical drive just means that only part of the "virtual" drive, whereas the physical drive refers to the whole thing.
• To perform the scan for data, click on the green scan button. Once this has done, recover all the data by saving it onto the system of your main drive. Depending on the health and strength of the external hard drive, you will be able to reinstall the data.
• If this does not work, then you will have to take your hard drive in for repair. If there is a mechanical issue then there is nothing you will be able to do. The majority of hard ware shops will repair hard drives for a price.