WD10 EZEX-00RKKA0 Cloning problem

I have an HP desktop running windows 7 and added the new internal drive to backup existing drive. As you may know HP has a C volume and also a small D recovery volume. First time cloning worked great. The whole drive was utilized with just the small 12GB D volume. The second time I cloned to this drive, the sizes of the volumes are wrong. The D volume is now huge with the C staying the same as the copied drive. I can’t find a way to change the size of the volumes that will make the C larger.
I’ve tried to decrease the D volume and doing that just makes unallocated space. The extend volume option for the C is shaded out. If I make the unallocated into a volume, I can’t seem to add the space to the C.
Help please

Typically on Windows 7, you can’t extend the system partition whilst the OS is running. You would need to boot from a different drive (maybe make a USB thumb drive that runs Windows?) to alter the Windows 7 partition. Or use third party partition software; there are plenty of choices out there.

Microsoft changed this in Windows 8.x and 10, so you might consider upgrading as well. (Windows 10 is free for a couple more days!)