Personal computer sales are wilting like lettuce on a Phoenix sidewalk in July, with this year showing the segment's biggest contraction on record, according to new projections by market researcher IDC. The firm predicts shipments will drop 10.1% in 2013 and another 3.8% next year before a slight uptick in the longer term. Tablets and smartphones are the "it" screens. The firm says commercial PC sales are expected to fare better.