Saving Demo Help. :(

Hi, i only have around 500 MB left on my C Drive and around 14 GB on my D Drive. Now Ive been trying to download the Call Of Duty 4: Modern Warfare Demo which is around 1.37GB. I'll try to save it on my D Drive then start the download , but i look at my C Drive space left and it starts going down when the D Drive's free space stays the same. Hope this all made sense. Srry if it didnt, but plz help.

topical cream