Spyware and Adware are two of the major annoyances for many computer users, slowing down PCs and obtaining information - all done covertly. Most computers connected to the internet will in fact be infected with some form of spyware, with users being blissfully unaware (apart from maybe a few strange occurrences whilst browsing). There are some formsof adware that will actually cost user dearly, which will be covered later on in the article.

Companies and individuals that create spyware applications often make huge sums of money, and yet claim to offer a valuable "free service" to innocent surfers. Spyware and Adware are essentially applications which can be bundled with "free" software or are installed in a sneaky manor, that serve to make someone a lot of money without the user knowing.