Microsoft continued to lose money on its Surface tablets throughout its just-concluded 2014 fiscal year, adding hundreds of millions of dollars in red ink and boosting total losses to $1.7 billion since the device's 2012 launch.According to the 8-K statement filed with the U.S. Securities and Exchange Commission (SEC) on July 22, the Surface posted revenue of $409 million for the quarter that ended June 30. But unlike the two quarters prior, Microsoft did not reveal the cost of revenue associated with the Surface for the period.