Today: A tech renaissance on Wall Street pushes the Standard & Poor's 500 to more record levels and several Silicon Valley companies to 52-week highs. Also: Personal computer sales dip the most in nearly two decades.

New 52-week highs across valley help push indexes to new records

While the Dow Jones and Standard & Poor's 500 have sprung to records in 2013, technology companies have not been as successful on Wall Street, with Apple's (AAPL) fall keeping the SV150 index of Silicon Valley's largest tech firms in negative territory for the year and the Nasdaq trailing the gains of its brethren indexes by a wide margin. The last two days have changed that dynamic, however, with valley stocks such as Yahoo (YHOO),