If you still have any doubts about having totally got rid of the root of the problem I recommend the spybot forum. the help I received there I was stunned by. Just over a year ago my son managed to **** up my machine when he clicked onto an "image" that a friend recommended him. It caused all sorts of damage and even when I thought I had rectified things I had all sorts of things still going on on my machine (eg a rootkit had been installed).

Really really helpful - my spybot experience and the general forum is at spybot forums