Lenovo has taken the crown from Hewlett-Packard to become the world's top seller of PCs, research firm Gartner said in a study released Wednesday. Lenovo took the top spot during a quarter in which PC shipments dropped due to a weak economy and pressure from mobile devices. Of the top four PC vendors, only Lenovo was able to grow its shipments. Its PC sales increased by almost 10 percent to 13.7 million units, giving it 15.7 percent of the market, Gartner said.