Anti-spyware

SuperAntiSpyware

Thorough detection and removal rate. The free version offers on-demand scanning only

http://www.superantispyware.com/

Download link; http://download.cnet.com/SuperAntiSpyware-Free-Edition/3000-8022_4-10523889.html

MalwareBytes Anti-Malware

Effective trojan detection and removal. Less effective on other malware.

http://www.malwarebytes.org/mbam.php

Download link; http://www.majorgeeks.com/Malwarebytes_Anti-Malware_d5756.html

A-Squared

Regular updates. Includes AV scanning. On demand scanning only

http://www.emsisoft.com/en/software/free/

Download link; http://download.cnet.com/A-squared-Free/3000-2239_4-10262215.html

SpywareBlaster

A very simple security program that helps block malicious content. For Firefox and many other browsers it mainly just blocks bad cookies from a list of specific sites. For Internet Explorer (IE) and browsers that use the IE engine it uses a list of restricted sites to block bad cookies, prevent the installation of activeX spyware, and prevent downloads/scripts/browser exploits. It doesn't seem to support Opera/Chrome/Safari.

I've used this for over 4 years and never have spyware on my system. Update it and Enable All Protection and close it. That's it! No scanning needed. It places kill-files to stop the crud before it gets you.

http://www.javacoolsoftware.com/spywareblaster.html