You might also consider going the hardware firewall/router path. Mine is a
Linksys with which I have zero trouble. Expect to pay around $80.00 or so. IMHO it is money well spent.
The other advantage of the firewall/router is that you can connect more than one computer to the internet without needing to pay your cable ISP addition connections. (Since you pay, at least in the case of ATTBI, for each IP addresse in use.)
Setting up the router is very easy provided you read the short manual ahead of time and follow the instructions on obtaining the fully qualified domain names for your ISP's mail and news servers.