Over 92% of computers are infected with Adware and spyware. Such software is rarely accompanied by uninstall utility and even when it is it almost always leaves broken Windows Registry keys behind it. Even if you have an anti-spyware tool your Windows Registry might be broken – developers of those tools are focused on removing Adware and spyware functionality, not every trace of software itself. Another category of software that is known to leave bits and pieces behind on uninstallation is games. There are a lot of special installation systems that creates strange files, unique entries in your registry file as well as changes system dll’s to other versions.