Main concepts and history of operating systems, main tasks and classification of operating systems, core and working principles, management techniques of virtual memory, reasons and solutions for system errors and lockdowns. Differences between operating systems (Windows, Linux, Unix, MAC OS), Disk management and fault tolerance systems, setting up an operating system and managerial commands, general functioning of operating system and desktop concepts, control menus and programs, file operations, user and group operations and its management, sharing files and printers, monitoring the system performance, security, preventing virus, harmful codes etc. and backup operations. Set up, usage and management of Windows and Linux operating systems.