With PC sales continuing to slide, NPD Group is reporting that Google (GOOGL -0.48%) Chromebook sales represented 25% to 30% of PC sales below $300 in the first quarter. Microsoft (MSFT -0.12%), which has clearly felt the pinch of lagging PC sales, has been focused on the tablet market to find a new source of growth. With Chromebooks becoming the fastest-growing segment in the PC space, this is bad news for Microsoft. Google continues to improve on the Chrome OS, making it an ever-imposing contender.

In the following interview with the Fool's Alison Southwick, Fool.com contributor Doug Ehrman discusses the importance of the Chromebook segment and why Microsoft should be worried.