I didn't see your specific installation method, but there may be several reasons for such a large capacity occupation:

First, your system is not completely installed, just upgraded. Or the C disk was not formatted when the system was installed. That is, when the system was installed, the original system was still there.

Second, your system is really newly installed, but the memory is too large, such as 16G or even larger. The default paging file and hibernation file are both as large as memory. If your memory is 16G, these two files will take up 32G of hard disk space.

Third, there is something wrong with the system, which is more troublesome. Try replacing a version and reinstalling it.