The missing peice of info is how the drives are divided and what the free space on C: is. If its a case that you just have too much stuff on D, and there's room on C, then we move it. If its too much stuff on D and there just no room at the inn..... well then its time to look at an external drive (which have gotten very cheap) for items that you dont need all the time. Or its time to get a second drive (E) that is a large storage drive.