Can you please give us more information, the more the better. Is he using windows 98 or XP Pro./Home and has this problem always been there or just started to happen, if so what was the last program he installed or downloaded?
Has he made any recent changes, or additions to his PC, if so what? If you will supply as much information as possible, even if you don't think it is relevant, someone will be able to help you and most likely cure this problem. Regards. j