Adware

Adware is software which goes beyond the reasonable advertising that one might expect from freeware or shareware. Typically a separate program that is installed (with or without the user's permission) at the same time as a shareware or similar program, adware often will continue to generate advertising even when the user is not running the originally desired program. Adware manifests itself as pop-up webpages, unwanted toolbars, and other pop-up ads on your computer screen. Fortunately, all known adware can be deleted with adware removal software, much of which is freely available.