Hi SRS why doesnt your friend with the troublesome housemates just set up a guest account and then go in as administrator and use the gpedit.msc console to lock down absolutely everything that should'nt be added to, moved or changed in any way for that account. (start-run type gpedit.msc and then go to user configuration, administrative templates and work through these...... the usual cautions about not changing anything you dont understand apply here though)
That aside I find this kind of thread quite educational. What I can never work out is why people persist with these dodgy Microsoft operating systems?
Using my Mac I have zero, zilch, nada, nyet, nothing..... problems with adware, spyware, viruses or other unwanted junk like that described above. The time and money I dont spend trying to manage these issues are more profitably spent on other things.
So if the point of using a computer is so that you can do things and be productive, why would you bother?