Deleting Partition on hard drive

My computer has a manufacturer installed partition–drives C and D. Currently on C I have 335 MB free the C drive is 13.9 GB. D drive has 165 GB free the size of D is 166 GB. My question is how difficult is it to remove the partitiion and should I. The computer is used for personal use only. I have an external hard drive which we bought when we thought we were running out of space on the C drive–only to learn that Sony VAIO partitioned it. I am a NOVICE. So any light that can be shed on this situation would be helpful!

See your other thread

Please do not crosspost. :cop: