A method for automatically changing a version of a client agent for a non-administrative user account without rebooting the user's machine uses a service having installation privileges. The service executes on the client and installs a client agent. The client agent communicates with a network appliance. The client agent detects a difference between its version and a version of the client agent identified by the network appliance. The agent signals the service that it has detected the difference and, in response, the service executes an installation program that installs, without rebooting the client, the version of the client agent identified by the appliance. A corresponding system is also described.