The best way (according to Computing magazine) is to install and occassionally run(depending on your internet usage) a program that will detect them in your system and eliminate them. They recommended Ad-Aware 6.0 as being one of the best ones available, and I have been using it with a great deal of success. YOu can download a personal version for free at Tucows, or simply click on the link below to go directly to the site.