That may not be all that you need. Since many computers now spend much or all of their powered-on time connected to the Internet, you might need to guard your system from Internet hacking activity. This does not mean that just because your computer is on the Internet, it is vulnerable to being taken over by some netcriminal who will steal your best games, suck all the money out of your Quicken accounts, and erase your hard drive. Any Internet-connected computer can be negatively affected by targeted network activity in the form of a denial of service attack. Most personal computers fall somewhere in between these extremes, and the measures you need to take to safeguard your system depend upon its Internet capabilities, its purpose, and on the time it spends online.
Internet security is viewed by some as an oxymoron equivalent to military intelligence.
It is incorrect, however, to fault the Internet for a lack of security, since it was never designed to be secure. Instead, it was expected that any needed security would be maintained on the client systems that connected to the network. For disparate computers to interoperate, they must speak a common language. Breaking down this barrier to access opened the door to hacking, but at the start of the Internet, hacking as we know it today was not an issue. The network was limited to a small community which participated in military defense research, and was a closed group whose members were familiar to each other.