Delete Protected Partition
When unable to extend volume due to a partition being in the way you may need to delete it.
If the partition is protected such as a recovery partition you will need to use diskpart.
Use the following commands:
diskpart
list disk
select disk <disk number>
list partition
select partition <partition number>
delete partition override
Using the ovverride option will allow to delete protected partitions, use with caution. You cant delete the system partition, boot partition or any partition that contains the active page file or crash dump.