An agent loaded in a computer's operating system (OS) simulates disconnection and reconnection of a device, with no need to actually disconnect the device logically from a computer. During simulated reconnection, when the OS requests the hardware ID of the device, the agent returns a substitute ID, which causes the OS to load a substitute driver. Substitution of the ID also allows driver substitution for a not yet logically connected device; in this cases, no simulated disconnection or reconnection is needed. Driver substitution is dynamic and reversible, with no need to restart the system or reboot the OS and substitution of a driver for one device of a type does not disturb other devices of the same type. The invention may be implemented entirely in software, with no need for hardware modifications or device customization.