Format external hdd with two operating systems

I have a hdd on a docking station that's connected to desktop via usb, and the hdd has two OS's on it (Windows 10 and Linux Mint). What's the best way to reformat the hdd completely? Thanks!

Open a Command Prompt with Admin privileges ("Run as Administrator") and run the following commands:

Code:

diskpart
list disk
select disk # <-replace # with the actual number for the USB hard drive
clean <- this will erase the disk selected above, make sure it is the USB hard drive!
convert gpt
create part pri
format fs=ntfs quick
assign
exit
exit

Thanks for those nice, clear instructions, NavyLCDR. It worked great!

Glad it worked for you!