Turning off your cable modem is not recommended or necessary. If a cable modem is turned off for any length of time, when it is turned on again, it may take several minutes to be recognized by the Road Runner network. The network must recognize the cable modem before the modem can transmit data. Windows NT users should ensure that all ports are secure so your computer cannot be used to relay SPAM, and intruders cannot gain unauthorized access to your computer 6. Make sure you have all of the latest security patches for Windows and Internet Explorer 7.
Firewalls come in both hardware and software based versions.