Microsoft dominated PCs and Nokia mobile phones, but both are irrelevant in the dominant model for tech in the next decade, smartphones and tablets. An acquisition may have been necessary, but by itself it solves nothing. Smartphones are now half of all mobile phone sales, and the 255m smartphones and tablets sold in Q2 2013 dwarf the 76m PCs sold. Microsoft now powers less than a quarter of all the personal computing devices being sold. Microsoft retains a leading position in enterprise and in console gaming. But if it cannot return to relevance in consumer, the strength of the whole business will suffer.