Sorry it is still not clear what you want.
The kind of modem built into a laptop was usually used to connect to the phone network (for dial-up internet) but this system is rarely used now.
A cable internet feed will use an external modem which is usually connected to the computer via an ethernet link or via a router.
An ADSL internet feed may use a separate modem but the modem is usually built into the router. Again this is an external device connected to the computer by ethernet or wireless.
Try to explain what your situation is. Is it that you need the driver for a Network Interface Card that is built into the computer -- go to Sony's support site for that.