HP took the number-one position in the US for the first time since 2001, thanks to sales of consumer PCs and improved channel programs in the business market. HP displaced Dell, whose market share tumbled 16 percentage points. Gartner said Dell had been "severely challenged by tough competition in the retail space" and the weak professional market. Again, Acer came in a close third thanks to growth in low-priced mobile PCs. You can read Gartner's full postmortem here. ®