[DUPLICATE] Trouble resizing disk drive

I have tried to use both DD 11 & DD 14 without any success in resizing my disk drive. What I have is a 500 GB disk with a 100GB "C" partition and a 400 GB "D" un allocated partition.What is strange is that is shows as 2 disks with Acronis disk 1 and disk 2, so I assume that is where the problem lies, as I can access either partition seperatley, but I can't figure out a way to use the un-allocated space on D to increase the size of C?

Issue is discussed here.