FireWalls
If you are sufficiently computer literate to get on the internet, you probably already know what firewalls are supposed to do and why they are called firewalls. However you may not understand how they are best installed and used.
I often hear the computer novice claim that his router has a firewall that is fully operational and protects his computer. It is not until he answers a few questions about how it got installed that he discovers he is not as well protected as he thought.
When you consider firewall installation and setup, the novice nearly always is daunted by the need for a list of all the IP addresses and services that should be blocked. This is a backwards approach. You don’t block unwanted IPs and unneeded services. You block everything. Then you enable IPs and services on an ‘as-needed’ basis. How can you tell something is needed? Well, one way is to launch your program that needs external access. If it works, all is well (maybe). If it does not work, then it may require an address or port be allowed to pass through the firewall.
Even that is a rather tough way to set up your firewall. It is better than researching for all the addresses and services that need to be blocked, but it requires a good knowledge of your application software and its requirements to create access through the firewall for a specific purpose.
It would be nice to have a program that identifies application software seeking external access. I use Tiny Personal Firewall to do that.
Tiny Personal Firewall is a program that runs in the background under windows and identifies and alerts when application programs attempt to gain external access. There are other programs like Tiny Personal Firewall that provide a similar function but I am only familiar with Tiny.
As with all good firewall installations, the Tiny installation blocks everything initially. Then, as applications make themselves known, the firewall allows you to grant access either one time or permanent and allows you to customize the access as well.
I consider programs like Tiny Personal Firewall to be an important part of a complete firewall. They take care of programs that try to call home.
I would also recommend the use of Ad-Aware to clean out software that is adware.
More good information on firewalls and firewall testing can be found here