If an external hard disk does not work properly, you should try to troubleshoot your problem by checking the USB cable, the port where it is plugged in, the power source, and if the drive is recognized in the Disk Management. It is advised not to format or initialize the drive in case there is any valuable data on it. In case the drive is recognized but the files are not accessible, data recovery tools can search for valuable files on that drive. Notchox is one such tool that can help recover pictures, documents, video, and other files from compatible external drives.