Diskpart is a Recovery Console command used to create or delete partitions on hard drives.
/add = The /add option will create a new partition on the specified hard drive.
/delete = This option will remove a specified partition on a specified hard drive.
diskpart /add DeviceHardDisk0 10000
In the above example, the diskpart command creates a 10,000 MB partition on the hard drive located at DeviceHardDisk0.
diskpart /delete DeviceHardDisk0Partition1
In the above example, the diskpart command will remove the Partition1 partition located on the hard drive DeviceHardDisk0.
diskpart /delete E:
In the above example, the diskpart command will remove the partition currently assigned the drive letter E.