then check the routers cables to the phone socket is connected correctly. Micro filter must be first into the Telephone socket on the wall. Any make shift temp tel ext's are dodgy they don't last for ever.
Have you started using the laptop in a different location within you home maybe and the signal of the router is bouncing not getting good reception to the router.
Please post back and tell us who you use for your broadband, what make and model of Router you have if known and arrangments of sockets within your house.