Hard drive full, but files / folders don't add up to used drive space [duplicate]

My harddrive is full, but according to the size of all my folders, I should have more than half of my drive left over.

Short Answer: WinDirStat

https://download.cnet.com/WinDirStat/3000-2248_4-10614593.html

NOTE: When you run it, make sure to "Run as Administrator".

Long Answer: Unfortunately Windows Explorer (File Explorer) was dead wrong about the size of my “Program Files” folder. It said that my “Program Files” folder was 16.5 GB. However, inside of it I had an .LDF file that was over 200 GB! Within about five minutes of starting WinDirStat I could see what was hogging up my drive space.

https://community.spiceworks.com/topic/1887054-storage-does-nt-add-up-in-windows-10

https://social.technet.microsoft.com/Forums/office/en-US/f91041e3-7e60-4193-a014-2dcf62bf1a4a/hard-drive-full-but-files-dont-add-up-to-used-drive-space?forum=w7itprogeneral