Program Directory Size is one of the most interesting and perspective programs in the field of the analysis of disk usage and disk space. The program is very simple in usage, interactive and subordinated to the principle «how to help in solving a problem». To help quickly, effectively not forcing the user to spend a lot of time for program mastering. Probably, many of you have noticed how it’s unpleasant to work with the program to which it is necessary to master during more time than to execute the basic procedures for the sake of which the program has been created. Directory Size analyses disk usage and disk space within few minutes and it doesn’t take much time master the program. The program consists of four windows. In the first, small one, the general help information on distribution of disk space in the PC is presented: how many gigabytes are free (and spent) on disks C, D etc. The second program window is the window of the work directory choice. All you need to do is to choose the directory (or the disk) in the menu Scan–Scan a folder. The program works with disk and folder structure by the principle of folder tree. Differently, each folder includes the folders, these folders includes the folders of the next level, etc. After you’ve chosen a necessary folder, the disk usage program analyzes its maintenance and represents the results in a separate window – top left one. In this the user can see what folders and files are included in the investigated directory, their size, quantity, extensions. The program allows to analyze the received structure using such tools as sorting, filter as well as to create tops of files and folders on extension, volume, etc. In the last window (bottom-right) the user can look through the received results in the kind of pies and bars.