This often happens when downloading a utility like Windows Live Plus.
These utilities often come with the option to install 3rd party extras, which, more often than not, are little more than Spy-ware, which do exactly what your friend is experiencing.
I had to drum into my wife and step-chidren, when installing these utilities, to un-tick the box that gives the option to install these useless extras.
Unfortunately, there's not a lot that can be done after-the-fact, so Henry Ham's solution is probably the best one.
Afterwards, drum it into your friends' head about those pesky 3rd party extras!!