If you are trying to shrink the C primary while in Windows you will run immediately into a problem with certain unmovable system files. While some workarounds may see results there are two things to point out here.
The first is having the available free space on that partition to allow it to be reduced in size. The second is the usual recommendation to back things up before attemping any changes to the existing partition scheme.
The best method once you have everything backed up is to use a 3rd party drive partitioning tool to see the primary reduced in size. Once that is done the next partition would have to be moved towards the front of the drive to fill in that space before you can expand that or proceed to move the next as well.
