Microsoft chairman Bill Gates says he's never had a computer virus, but that adware and malware have him ticked off enough that <A HREF="http://www.eweek.com/article2/0,1759,1666300,00.asp">Microsoft plans to do something about them.</A> Speaking Friday at the Computer History Museum here, Gates said the industry is "halfway to solving spam," with good filtering available but the message authentication piece remaining to be solved.