The Avast! Cleanup Tool is a third party program that is not to be confused with the company's official removal program Avast! Uninstall Tool. Sometimes, they combine the list with searches to make sure that all program files and Registry information are removed from a computer system. These tools use hard coded lists of files and locations usually and are considered thorough because of it. The majority of companies that produce security software for Windows make available removal tools that delete all traces of a product from a system. It can be that the default uninstaller that ships with the program is broken and thus non-functional, or that it leaves traces behind that prevent the installation of an update, other version or third party product on the system. Security software sometimes may not uninstall properly on a system it is installed on.
