Investigate disk space usage with TreeSize

Tree Size is a free appliation which helps you to find where precious Hard disk space has gone to. It can be started from the context menu of a folder or drive and shows you the size of the selected folder, including its subfolders. Each folder can be expanded in Explorer-like manner to view the size of its subfolders. Scanning is done in a thread, so you can already see results while TreeSize is working without having to wait.

The wasted space can be written up in a printable report, giving you some idea of a pattern for the necessary alterations.