An agent software application for controlling distribution of files and managing updates to files. The agent automatically downloads files upon request by a user and can download a file in multiple portions by tracking received byte numbers. The agent searches for updates to files by using application signatures to uniquely identify files stored on a user's machine and transmitting the application signatures to a server storing the updates. The user can set parameters related to control of the downloading and searching for file updates, including scheduling of downloads for selected files and scheduling of automatic searching for updates on a periodic basis.