In generating a task environment by a thin client system, it is desired to reduce the man-hour of the operation of the system construction and setting. Specifically, a task environment setting table stores task environment conditions for every projects or task forces. A task environment setting section automatically performs the settings required for task at the timing when the desktop environment generation section generates the desktop environment in accordance with the setting in the task environment setting table. Before a user makes a connection with a desktop environment via a session management section to start a task, the session management section performs setting to a task environment generation agent for each user. As a result, not only a simple desktop environment, but also the environment for the task is automatically set.