Hey Tess Hon;
We have cable and had them come out and replace their modem once over a year ago since it was still under warranty. The cable guy told me if we have probs after the warranty runs out to consider buying a modem since the ones the cable company provide are not very good. He suggested the Morotola Surfboard Modem SB-5120, and he said you can usually get them at WalMart for $59. We have not had any further problems, so I'm still using the cable company modem.
Does your TV go out when the internet goes out? If not it may very well be a modem problem. Good luck you sexy thing....
Joe