These SEDNTERP supplementary density and viscosity data files/graphs (Origin .ORG files), and the Origin fitting template files, are distributed as a compressed Windows self-extracting ZIP archive. Simply execute the program density.exe and you will be prompted for a directory/folder in which to place the files (109 files, 2.2 MB after expansion). The default directory for these files is the default SEDNTERP directory, c:\sednterp.