The company that proclaimed the ?post-PC era? ? Apple ? is now the biggest maker of PCs in the world. That conclusion comes by way of Canalys, a research firm that has tacked against conventional wisdom in the tech analyst world by insisting that sales of iPads and other tablets belong in market share tallies for the computer industry. And so, as Canalys itself predicted in November, robust holiday sales of the iPad catapulted Apple ahead of Hewlett-Packard to make it the top PC company in the fourth quarter. The 15 million iPads and five million Macintoshes that Apple sold during the period accounted for 17% of the approximately 120 million PCs shipped during the fourth quarter, Canalys said. The firm said tablets accounted for 22% of total PC shipments during the fourth quarter, with Amazon?s Kindle Fire and Barnes & Noble?s Nook included. Without the lift from tablets, the PC market looked bleak during the quarter, declining 0.4% from the same period a year earlier. It looks as if one of the post-PC era?s star devices gave a gift to the PC industry over the holidays: growth.