Immediately after you start up the program you are presented with a directory selection dialog. Select a directory, then press OK, and disktective will start generating a detailed report for that directory.
Please note that when you select a root directory (such as 'c:\') a report for the entire disk will be created, including an extra node indicating the amount of free space on that disk.
A screenshot of the 'directory selection dialog'.
A screenshot of Disktective while generating a report:
Disktective after having created the report, with tree-pane and pie-chart shown: