1
Right click your Start Button and open Disk Management.
Expand the bottom pane so all drives and partitions are visible in the bottom pane.
Please provide a screenshot of that Disk Management window.
2
Download the free TreeSize app from the Microsoft Store.
Very Important - to run TreeSize, you must right click its icon and choose Run as Administrator.
Please provide a screenshot of your C drive in that TreeSize utility, so I can see your hard drive and work out where that space is being used and if there is an underlying problem.
Please ensure the full TreeSize window is in the screenshot, there is information on the top and bottom bars I needs to see.