Is the drive detected when attached to the other USB ports? Does the Windows 7 computer detect any USB flash drive? If is does do the following.
Download DeviceCleanupCMD. Unzip the file to a folder on your desktop. In that folder is a folder called X64, Copy the X64 folder to the root of C:\.
Detach the USB external if attached and any USB flash drives.
Open an elevated command prompt. Type CMD in the Search Box > Right click > Run as Administrator.
Type the following commands
cd c:\x64
devicecleanupcmd *
You will see all non-present USB plug and play devices being deleted. The next time to attach a USB device the driver will be installed again. Sometimes previous plug and play drives for USB devices conflict with each other.
http://www.uwe-sieber.de/files/devicecleanupcmd.zip
Edit: If the above does not work is there any data on the external you need. If so please back it up first on the Windows 10 computer and after the backup post back. I think this problem relates to a hibernation file Windows 10 may be placing on the hard drive.
Edited by JohnC_21, 04 September 2017 - 09:46 AM.