|Is this "Secured Network" to which you refer your home wireless router? Did you set up the wireless and it's security? Is it possible the wireless security protocol or password has been changed? "refresh the driver" advice coming from an ISP's tech support sounds to me like they don't know what they're talking about. At least with my ISP they are honest enough to say they cannot help with anything downstream of the modem. Generally they do not offer assistance with router/wireless and LAN problems.|
If the secured network to which you refer is a mobile broadband service accessed using a USB wireless modem provided by comcast then they certainly do have a responsibility to assist resolve your problem. In this event I would suggest you uninstall any/all software that came with the modem, Uninstall the device in Devicemanager, reboot then re-install.
Goin' Fishin' (Some day)