Well, after the edit and insertion of the needed image, there are no surprises there. Presuming he's using D: for his data storage he has less than 4 GB allocated to that partition. His partition for Windows is smaller than I'd use at 150 GB, too.
Most of the space on that drive is unallocated, a huge 777 GB swath at the end of the drive.
I'd enlarge the Windows partition to at least 250 GB and add the remainder of the 777 GB to the D: partition so that you have space that's larger than your average jump drive for data storage.
I am a fan of MiniTool Partition Wizard Free for doing partition rearrangement, not that one cannot use the built in Windows disk management tool.
In this particular case you'll probably end up moving the Recovery Partition to the far end of the drive, placing the existing D: partition just ahead of the Recovery partition, expanding C: into the unallocated space so that it's 250 GB in size, then finally merging the existing D: with the remainder of the unallocated space to form a substantial data storage partition.
CRITICAL: Always do a full system image backup to an external hard drive before you begin playing with repartitioning a drive.
Edited by britechguy, 10 February 2018 - 12:57 PM.
Brian AKA Bri the Tech Guy (website in my user profile) - Windows 10 Home, 64-Bit, Version 1803, Build 17134
. . . the presumption of innocence, while essential in the legal realm, does not mean the elimination of common sense outside it. The willing suspension of disbelief has its limits, or should.
~ Ruth Marcus, November 10, 2017, in Washington Post article, Bannon is right: It’s no coincidence The Post broke the Moore story