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If I was you, I would backup any personal data and I would repartition disk from scratch. You would need to do a clean installation though. Are you using MBR or GPT partitioning scheme? If MBR, you can avoid the System Reserved partition by making sure the first primary partition is marked as ACTIVE (bootable).
PS - I strongly advise you to use lossless PNG format for screen captures instead of lossy JPEG.
Nothing wrong with it, Do you still boot into the old Windows? if you're not using the G: drive of Windows, you may want to Delete it and either extend the C: drive or create a partition for something else.
I still use the old Windows to refer to while I'm setting up the clean install. When I'm done, I plan to eliminate the old Windows partition and extend the new Windows partition to occupy the entire drive.
For Drive D: that is being used only for data there should be no problem, has only a single partition on it. Since it's not the boot drive the choices of MBR vs. GPT shouldn't be an issue, I usually just plug in a second drive and use Disk Management to create a partition [or more if desired] then format as NTFS.