Find File Explorer, which may be in the popup if you right-click on the Windows icon at the left of the tray. In "This PC" you will see OS (C:). Right click that and click Properties.
If i could see the exact capacity i had available or used on my SSD over past 2 months it would help me diagnose hugely.
That is what i am doing to see the space remaining and info on my SSD as well now as Samsung magician SSD software program i installed for testing along with another. I don't know where in the properties it shows the past history like a log tho.
However apart from the Trim being enabled on a hard drive it seems to have fixed itself. I will wait till Windows does more updates make sure there fully installed a few days later try disc cleanup again and see if i regain what space it claims ill get. I will also be keeping an eye on the Firefox cache folder which seems to sometimes get the same issue.