A set of PowerPoint slides that appear to contain details about the next version of Microsoft’s Windows operating system surfaced Monday. The slides indicate that Microsoft plans to tackle the long-running problem of Windows’ slow start-up time, in addition to placing cutting-edge technology such as facial recognition in the new operating system. Questions remain, however, about the authenticity of the material. The slides, dated April 2010, first surfaced on the Italian Web site Windosette.