Newbie needing to remove partition on 40G laptop running XP media

I am very new to this and very nervous. I am afraid I will wipe out everything! I have a 40G hard drive (laptop) that is partitioned into C: and D: drive. And need to remove the partition to make it just one 40G drive. I was told that I could “just” down load GParted and whoopee – simply remove it with the click of a key??  Reading everything on the home page and the posts – I see it is MUCH more involved than that!  Please, I need very simple “step by step” instructions as to how to remove the partition and save and keep all the data that is currently on the partitioned drive - but as just one drive. NOTE: There is only 325MB of space on C: now and 15G on D: now; so I can not download to C: please help me some one that has once been here also. Thank You