Best way to flatten & format a drive?

I used Hard Disk Manager 15 to migrate my C: drive over to an SSD, and now I want to format the old C: drive, but it is partitioned. What is the easiest way to create one contiguous NTFS space on this drive for other uses?

Thanks!

It's possible to start "wipe" the disk in HDM15, to interrupt after a few seconds and then create and format a partition on the hdd.
It's possible do in cmd. Run cmd as an administrator.
diskpart
list disk
Choose your old drive, eg 2
select disk 2
clean
then you can start HDM15 and then create a partition with it. or continue cmd.
if the hdd is more than 2 TB, you need to convert it to GPT
convert gpt
Next
create partition primary
select partition 1
format quick fs=ntfs