RidNacs

RidNacs is a free program (Disk Space Analyzer) for analyzing disk space usage on the computer. 

It searches individual directories, local or network drives and clearly displays the size of directories in a tree structure, so the user can quickly see which directories are taking up the most storage and are suitable for cleaning.
  Screenshot of RidNac
 
  Analysis results can be exported in various formats (XML, HTML, CSV, text file) so that they can be compared, for example, with subsequent analysis.
  Besides being easy to use, RidNacs is characterized by high analysis speed and low memory consumption.
  Features in RidNacs
 
      Clear analysis results via filegroups where files are combined down to a configurable size.
      Files can be opened and deleted directly in RidNacs.
      The file system is read in the background (multi-threaded), meaning you can already navigate the directory tree while browsing.
      The Explorer context menu is supported and allows calling additional programs, among other things.
      The appearance of the bar chart can be set to "skins".