I've just bought a brand spanking new desktop, running Windows 8.1 with 1TB of hard disk. I've copied all the files across from my old computer, into the new computer's My Documents folder. This has been stored in the C partition (also labeled Windows), which is 149GB. No data has been stored in the Data (D) partition, which has 762 GB capacity, totally unused.
My music and pictures and other documents have nearly entirely filled the C partition, meaning that, for example, iTunes refuses to play as it needs more memory to write to.
I figure that somehow I need to teach the computer to store information in the D partition, but I don't know how to do this. Can anyone advise me what I need to do, please?