WinDirStat is a disk usage statistics viewer and cleanup tool for Windows. WinDirStat offers an informative visual display of your hard-drive usage. WinDirStat assigns colors to each file type, such as MP3, ZIP, EXE, JPG, and etc. By default, the files that take up the most space are colored blue, the second heftiest are red, and the third largest green. Once identified where disk space has gone, it allows the user to easily decide space can be saved. WinDirStat includes features for managing files, such as the ability to automatically permanently delete files. This utility can be downloaded from here.