This PUP is not a cute cuddly puppy dog. This PUP (Potentially Unwanted Program) is a program that may be unwanted, despite the possibility that users consented to download it. PUPs include spyware, adware, and dialers, and are often downloaded in conjunction with a program that the user wants. PUPS sometimes come bundled with free software. They will display pop-ups or install a toolbar in the default browser which will change the homepage or search engine. Some of them will run other processes in the back slowing your PC or will display unwanted ads. To prevent installing a PUP always select the Custom Installation. Do not select the Standard, Express or any other installation that is recommended. When you select the Custom Installation you get options, already checked which include an unwanted Tool Bar or a default homepage.
Spyware – http://www.en.wikipedia.org/wiki/spyware
Adware – http://en.wikipedia.org/wiki/adware
Dialers – http://www.en.wikipedia.org/wiki/dialer