External hard drive is not being recognized by any computer

First make sure usb cable connected to harddrive is working fine.
try it in different usb ports.
Press windows key +R key so you can see run then type in run "devmgmt.msc" then press ok so you can see device manager uninstall all usb drivers then it automatic install usb drivers.
then check.
Also you need to change registry for that type in run "regedit" then press ok then you can see registry editor then locate below key.
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E965-E325-11­CE-BFC1-08002BE10318}
And remove upper filter and lower filter.Then restart computer then check.
If your harddrive still not recognized then you need to repair your harddrive.Try your harddrive in different computer if it is not recognized on another computer then your harddrive has internal issue.
Let me know if you need further assistance.
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