|I don't use itunes so I can't speak to that program except to say itunes does restrict what you can do with downloads so maybe you need to move the folder you store itunes files to the D drive. |
I suggest you go to the itunes site and look at their FAQ list for possible help. Or maybe they have a forum on their site.
If itunes is your only issue then let it download there. Just move other files to the
D drive. Post what you see in My Computer for total and free space for both the C & D drives.