John - no offence taken or intended. I was just making it clear that I am not a computer/internet newbie who clicks on every pop-up (I may have been so at some time past before I heard the warnings), and am looking for useful advice.
Thanks for your explanation of Hijack This. I have wondered for a while what it was supposed to be used for. Your description makes sense as something to run.
Would the advice be to run it routinely before and after installing new programmes, or is that just being over paranoid? Is it better used simply to compare things against the original state of the computer?

Quack!
GtD.