FWIW I agree with alexe3831 as far as being able to store data on C drive. However, unless you have or plan to have a dual boot system and/or create a recovery partition, partitioning a hard drive, when you only have one drive, really has no advantage. There are circumstances in which creating a partition specifically for pagefile can show performance improvements but, that really only applies if you have two physically separate drives. Even then there is not a lot of gained performance.
But, if you insist on "reclaiming" the partition, which I perceive meaning to delete it and expand D, fimbles instructions should work just fine.