You may think that the anti virus program you have will solve all you security needs. While it can help it is only one aspect of stopping spyware. Here where I work I have chosen to use three anti-spyware programs in addition to our anti virus solution to provide a safer computer environment in a public setting, although I use these my self to protect my computers.
One may think that because lab computers are locked down and, in some cases, frozen that these machines are safe. The sad truth is that they are at more risk than your home computer. The users of these computers are not worried about infecting the machines because it is not their machine. It is only prudent to add relevant and known security software to prevent known compromises and mitigate unknown. It is also a fact that no one tool or method of protection is adequate. As with protecting your health, protecting the health of a PC require various methods used together to provide an overlapping cloak of protection.
To that end I employ three free programs that work in different ways to protect the computers.
Spyware detection and removal, enhanced pop up blocking, block settings modifications, and blocks the installation of spyware quietly.
I only use a few of the many features this software has. I use the site blocking feature. This allows you to block sites that are known to be malicious, currently 32,572.
I also implement the hosts file augmentation feature. This feature allows me to place dead address statements in the host file to disallow access to the known malicious sites altogether. By doing this I keep the computer from talking to the site regardless of the threat, which may be a day zero threat and unknown to the previous feature.
Prevent the installation of activeX based spyware and other malicious software. Block known malicious tracking cookies in IE as well as Firefox. Do it all passively, causing no slowdown of the system.
Because these are installed on machines that have the disk structure locked the only one that can update itself is Windows Defender. However, during breaks it is easy to update the other programs and bring the protection level current.
This does not mean that we are secure, as with all security issues constant vigilance and reviewing of methods and measures must be done. Security is an ongoing process that will have its triumphs and failures.