For a thorough and clear answer to the eternal question of where all the space on your new disk went, consult TreeSize Professional. The interface allows you to easily find and delete files that waste space. TreeSize Professional analyzed disk usage quickly in our tests. You can analyze any folder by right-clicking it and choosing the Context Menu command. It displays files and folders both as graphs and as detailed lists. In Visual mode, you can choose between pie and bar graphs, as well as change colors for better legibility. The Detailed view lets you see statistics by user and file type. You can limit the scan to files created in the past however-many days. The program saves results in XML, HTML, and Excel formats, and the extensive functionality makes TreeSize Professional attractive for system administrators.
TreeSize can show you the size of a folder or drive from that item's context menu, recursively including any subfolders. In Explorer-like style, simply expand a folder to view the sizes of any subfolders. TreeSize works like the Unix command "du" (but with a Windows 95 graphic interface), does all scanning in a thread, and can display wasted disk space. It also lets you print results. Version 1.43 contains a new GUI, better support for IE 4.0, and some small bug fixes and enhancements.