External hard drive won't format

External hard drive won't format

Following the below steps at your own Risk....
first open the Command Prompt and type diskpart on it..
now the new window will be open
then carefully the below commands on it with fully understanding the 
below commands.....Best Of Luck.....
Hope it will work 100%.....

DiskPart <ENTER>
list disk <ENTER>
select disk X <ENTER> X=Disk Number
clean all <ENTER> Will take time
list disk <ENTER>
select disk X <ENTER> X=Disk Number
create partition primary <ENTER>
format fs=ntfs quick <ENTER> NO slash
active <ENTER>
exit <ENTER>
exit <ENTER>

Reboot and check Letter assigned in Windows Disk Management