to open diskpart:
PS> diskpart
list disk
it will give you something like this
DISKPART> list disk
Disk ### Status Size Free Dyn Gpt
-------- ------------- ------- ------- --- ---
Disk 0 Online 953 GB 7168 KB *
Disk 1 Online 1863 GB 0 B *
Disk 2 Online 28 GB 0 B *
you'll need to carefully select the correct one, Disk 1 in my case (2TB external Hard drive)
select disk 1
clean
create partition primary
optional:
list volume
select volume X ← (replace X with the number of the new volume, usually the last one)
lastly (you can change the label and the letter)
format fs=ntfs label="ArcLinux" quick
assign letter=D
exit
you don't need to make partition if you want to boot an OS on it