I still reckon it is worth recommending AVG Anti-Spyware, Ad-Aware and Spybot, (after a full AV scan) If symptoms persist, or there are signs of rootkits, backdoors, Trojan downloaders, worms and other viruses, a reinstall/recovery is by far the safest option (particularly if the computer is used for internet shopping, banking etc.) But he is not the end of the story.