If you are having a similar issue with your PC's hard drive, you can try the fixes below. No matter the cause, if you follow the tips laid out below you should hopefully get the drive going once more or at least recover your data. Drive letter conflict or no drive letter.RAW, invalid or unsupported file system.First, check the causes that make your external hard drive not working: You don't have to buy a new external hard drive and give up all the precious data. There are many reasons why the drive has become problematic, such as these: If your external hard drive suddenly stops working or cannot be recognized by your PC, don’t panic. Causes of External Hard Drive Not Working/Responding The following solutions for fixing problems with external hard drives will work with any brand, including WD Elements, Seagate, SanDisk, Toshiba and others. Connect Non-Working External DriveĬhange USB cable, USB Port > Change PC.