Microsoft beat city expectations after posting positive second quarter results.
Gains from strong sales of video games and Windows Vista accounted for the upswing.
More than 100 million Windows Vista licences were sold since its launch a year ago. The enterprise, server and software tools divisions doubled revenue to £504m, in comparison to the prior year.
"We are in the midst of another strong year with great momentum heading into calendar year 2008," said Microsoft's chief operating officer, Kevin Turner.
Consumer products launched in the second quarter included Windows Home Server and new versions of the Zune media player. Sales of Xbox 360 consoles reached 17.7 million units, up 70% on the previous year.