How to Fix External Hard Drive Not Showing Up

Fix an external hard drive that won't appear on Windows, Mac, or Linux. Step-by-step troubleshooting for USB drives and external storage devices.

1. Check the physical connection. Unplug the external drive and reconnect it firmly to a different USB port. Try connecting directly to your computer rather than through a USB hub. Listen for the connection sound on Windows or look for the mounting notification on Mac.
2. Test the cable and power supply. Replace the USB cable with a known working cable of the same type. For drives requiring external power, verify the power adapter is connected and the LED indicator shows the drive is receiving power. Try the drive on another computer to isolate hardware failure.
3. Open Disk Management on Windows. Right-click This PC and select Manage, then click Disk Management. Look for your external drive in the list of disks. If it appears without a drive letter, right-click the partition and select Change Drive Letter and Paths, then assign a letter.
4. Check Disk Utility on Mac. Open Applications > Utilities > Disk Utility. Look for your external drive in the sidebar. If it appears grayed out or unmounted, select it and click Mount. If it shows as unformatted, you can erase and reformat it here.
5. Update or reinstall drivers. Open Device Manager on Windows by right-clicking the Start button. Expand Disk drives and Universal Serial Bus controllers. Look for devices with yellow warning triangles. Right-click any problematic devices and select Update driver or Uninstall device, then reconnect the drive.
6. Run disk repair utilities. On Windows, open Command Prompt as administrator and run 'chkdsk /f' followed by the drive letter. On Mac, select the drive in Disk Utility and click First Aid. These tools can repair minor file system corruption that prevents mounting.
7. Format the drive as last resort. If the drive appears in disk management but won't mount or shows errors, formatting will erase all data but restore functionality. In Disk Management, right-click the drive and select Format. Choose NTFS for Windows-only use, exFAT for cross-platform compatibility.