When you run GraphVu Disk Space Analyzer for the first time, it scans all disk devices connected to the computer and creates a graph for each disk volume.
Initial scan may take a long time (depending on the size, speed and number of disks) so please be patient.
When the initial part of the scan (defined by the Initial Scan Depth setting - see General Settings tab) is finished, Disk Space Analyzer will open its main window and continue scanning the first disk volume (which is usually disk C:) until the full scan is complete (see also Scanning Folders).
Related Topics
Explains how you can force a full rescan on the start of the application.
Explains how you can change initial scan depth.
Read more about update scan.