Hi ObnoxiousGolem,
I am Dave, I will help you with this.
Click the link below to download a small free utility called Treesize.
https://www.microsoft.com/en-us/p/treesize-free...
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.