In your Windows operating system based computer, you can use multiple hard drives to store various data or files. These hard drivers are of different storage capacity. But problem comes to you when you try to install or plugged an external hard drive to the computer and it shows that External hard drive is not recognized in Windows8.1. It is really a very critical error issue that comes to you due to many reasons like incompatibility, damaging of the hard drive, virus infections, bad boot sector, etc. You can fix External hard drive not recognized problem in Windows with the help of some manual or automatic error fixing methods. For automatic fixing, you can also use Advanced System Repair tool in the computer.