Anti-spyware is software that protects computer users from spyware and other unwanted software. Anti-spyware programs secure the computers against the effort of malicious spyware, to take partial control of, or intercept a computer’s operation without the user’s consent or knowledge.

Anti-spyware programs offer real time protection, and scanning and removal. Real time protection functions similar to real time anti-virus protection. That is, the program monitors all incoming data by scanning all the files that the user tries to download from the Internet, and blocks the activity of components that represent spyware. Real time protection also blocks any unauthorized attempts made to install startup programs or to change the browser settings. The scanning and removal features offered by most anti-spyware programs are simple. The program scans the contents of the operating system files, Windows registry, and installed programs and removes any entry or file which tallies with those in the already existing list of identified spyware components.

Anti-spyware programs also require a frequently updated database of latest spyware components. Whenever a new spyware is released, the anti-spyware developers discover and evaluate them, and create “definitions” or “signatures” which help the anti-spyware programs to identify and remove the spyware. Hence, it is highly recommended to update the anti-spyware program frequently to ensure protection.

Major anti-virus firms including McAfee, Symantec, and Sophos have added anti-spyware features to their existing anti-virus products.

Anti-spyware programs of recognized companies are usually not available for free use; occasionally the manufacturers allow a free trial, enabling only certain features. Very often they only provide free scanning; the actual removal of the spyware is possible only with a registered version of the product. Because fake anti-spyware programs that are actually spyware exist, one should not be put off by the price of legitimate software and the protection it offers.