The consumer-electronics giant gave its all-in-one Vaio W desktop computer some additional punch Monday. Sony announced the $1,600 Vaio PCV-W20 PC, which comes with a 1.8GHz Pentium 4 processor, 512MB of memory, an integrated combination DVD and CD-RW drive and a 60GB hard drive. The W line wasin United States in early October and is built around a 15.3-inch liquid-crystal display and a keyboard that folds up in front of the screen. When the keyboard is folded, the W can play music via built-in speakers. The unit will begin selling in the United States in March.