As long as they are all DOS (Windows) partitions, just use FDISK
Do this order:
Delete Logical Drives
Delete Extended DOS partition
Delete Primary DOS partition
Create Primary DOS partition
It'll ask if you want to make it 100% of the disk and active, say yes.
Then format the partition and you're good to go.
If you have non-DOS partitions on there you might have problems, FDISK can be unfriendly to non-DOS file systems.