The Ericsson F5521gw is a mobile broadband modem that allows a Toshiba device to connect to mobile networks. The Windows driver allows the system to communicate with the modem for data transfer. To install it, download the appropriate driver from the Toshiba or Ericsson website, run the installer, and follow the on-screen instructions. After installation, restart your computer to ensure proper functionality. Are you encountering any issues during the installation?