I don't know how much you know about this so I'll try to see if this works with full details.
Click start. in the search box type cmd
, on the cmd entry that appears, right click it and select run as administrator. (called an elevated command prompt)
in the box type diskpart and press enter, it will take a few seconds, but it will answer diskpart
type list disk
and press enter - hopefully tour drive will show up with a number assigned to it. example 1 select disk 1
(or whatever number diskpart assigns it
) it will reply disk 1 is the selected disk. Be sure you select the corect disk.
type clean all
and press enter. go have lunch. it will take several hours, but the drive will be wiped completely. It will look like nothing is happening but it is. There is no progress account until it is finished. It should take 3-5 hours.
Assuming it is a data or storage drive. When it completes
(not really necessary, but to be sure) type select disk 1
again and press enter
type create partition primary
press enter -response should be the selected partition was created
type select partition 1
press enter format fs=ntfs quick
and press enter
and press enter. To assign it a drive letter exit
-enter to leave diskpart and go back to the command prompt exit
enter to leave the command prompt
If all that completed your drive should be ready to go. and should show up in disk management and explorer.
It should look similar to this but, type assign and not active unless you are going to install an operating system on it.