Step By Step Revive Your Undetected External Hard Drive

Connect the hard drive to a different USB port on the computer.

Unplug the USB cable from the port that is being used on the computer.
Try to connect the USB cable to a different USB port on the computer.
Make sure that the newly tried USB port is working properly and that there are no problems with the connection or port.

Test whether the issue is related to a specific USB port.

By connecting the hard drive to a different USB port, you can determine if the problem occurs due to a specific USB port on the computer.
If the hard drive is successfully detected when connected to another USB port, then most likely the problem is related to the USB port that was previously used.

Check Device Manager to see if the hard drive is listed there.

Open Device Manager on your operating system. You can access it by typing “Device Manager” in the Windows search menu and selecting the appropriate option.
Look for the section related to disk drives or USB drives.
Check if your external hard drive is listed there. If it is registered, it means that the system recognizes the presence of the hard drive, although there may be other problems that cause it not to detect normally.

If listed but has an exclamation mark or question mark, update or reinstall the driver.

If the hard drive is listed but has an exclamation mark or a question mark next to it, it indicates that there is a problem with the hard drive driver.
Right-click on the name of the problematic hard drive and select the option to update the driver or reinstall the driver.
Follow the instructions that appear to complete the driver update or reinstallation process.
When you’re done, try reconnecting the hard drive and see if the problem is resolved.

Use a utility such as Disk Management in Windows.

Open Disk Management by typing “Disk Management” in the Windows search menu and selecting the appropriate option.
Locate your external hard drive in the list of disks displayed. Perhaps the hard drive will appear as an unallocated disk or have an unusual status.
If the hard drive appears as an unallocated disk, you may need to reallocate space or create a new partition.
If the hard drive has partitions but has problems, you can try using formatting options or repairing existing partitions.
Follow the instructions that appear in Disk Management to perform the appropriate action according to your hard drive situation.

Trying to detect and fix partition or format issues.

After performing the necessary actions in Disk Management, reconnect your external hard drive and see if the problem is resolved.
If Disk Management successfully detects and fixes partition or format issues, you should be able to access the hard drive and the data stored on it as usual.

Connect the hard drive to another computer.

Unplug the USB cable from the current computer.
Bring the external hard drive and USB cable to another computer that works properly.
Connect the USB cable to an available port on the other computer.

Test whether the problem is related to the computer or the hard drive itself.

After connecting the hard drive to another computer, monitor whether the hard drive is well detected by the operating system.
If the hard drive was successfully detected and you can access the data on it, most likely the problem is related to the computer it came from.
However, if the hard drive is still not detected or is experiencing the same issue, it indicates that the problem may lie in the hard drive itself.
By knowing if the problem is related to your computer or hard drive, you can narrow down the cause and take appropriate steps to fix it.