External hard drives back up your most important files, but what happens when they malfunction? Here's what to do if your device is not detected in Windows.
There are several reasons why an external hard drive may not be accessible or detected when you connect it to your computer.
While it is possible that your external hard drive may have come with bundled software that may be incompatible with newer operating systems, this is typically just ‘back up’ software, and the drive is not dependent on that software to function. The external hard drive itself, under normal circumstances, should be detected by your operating system, without the need for drivers, software, or firmware updates.
If your external hard drive is not accessible please try these basic troubleshooting steps first.
Basic hardware troubleshooting steps:
Try connecting the drive to a different port on the computer.
If possible, try using a different cable.
Try using the drive on a different computer.
Verify the drive light is on. Desktop Drives typically require a power adapter. No light could indicate the power adapter is not connected to power.
Try a different power outlet. (Desktop Drives)
If using a surge protector or power strip, plug the power adapter directly into the wall outlet instead.(Desktop Drives)
Check both Device Manager and Disk Management in the Computer Management console:
On your keyboard, hold the Windows Key () down and press R.
Type compmgmt.msc into to the run box.
Click on Device Manager on the left.
First, check the Disk Drives section in the middle window by double-clicking it.
Look for your drive name. If you see the drive is detected here continue reading. If not, click here.
Right-click on your external drive listed under Disk Drives.
Click on Properties.
Click on the “Volumes” tab.
Click on Populate.
Document the disk number provided in this window (Disk 1, Disk 2, etc…).
Now click on Disk Management on the left-hand side. This will allow us to view the drive’s health.
In the middle towards the bottom locate the disk number from earlier.
Once you have located the drive you will want to look for the following:
Does it show RAW or Unallocated? Either of these indicate a possible issue with the drive’s formatting.
If the drive shows as RAW or Unallocated and you have already tried a different port, cable, and computer but you need the data, then you will want to consider data recovery. If you do not need any data from the drive, you should be able to reformat the drive to restore accessibility. Read our How To Format Your Drive article for instructions on the process. WARNING: Formatting erases all data on the drive.
If the drive is formatted correctly for Windows you should see the following information:
NTFS - If NTFS is missing then the file system has become corrupted. You can format the drive if you don’t need the data.
Capacity - Check to see if the drive is correct, for example, if you have a 1 TB drive it should say 931 GB.
Drive letter - Verify that the drive has a drive letter. If it is missing, verify that other drives have a letter. If other drives have a letter but the external is missing then you can right-click and select change drive letter or path.
Click Add then assign a letter and OK.
Drive not detected troubleshooting:
If the drive was not detected under Disk Drives then check the following:
Within Device Manager look for any entries called unknown device, another device, or mass storage device with a yellow ! icon. Important - Make sure to expand the Universal Serial Bus controllers section so you can see entries there as well.
If you see an unknown device or other devices then right-click on it and select properties.
Under the general tab locate ‘Device Status’ and there may be an error code.
You may see a code 10 or 28.
If you see Code 10 and have already tried another cable and computer then the drive has probably failed. If you need the data on the drive, then you will want to consider data recovery. If you do not need the data and the drive is still within warranty, you will want to have the drive replaced. Visit the Warranty and Replacements section on Seagate.com for further details.
If you see Code 28 (this may work for other codes too, i.e. Code 43) then try the following:
Note: If that fails, you will need to try to reload the USB drivers for the operating system by inserting your Windows Media, rebooting, and attempting a Repair/Restore.