Microsoft has bundled the latest Windows 10 Insider Preview build with a number of major (but still experimental) features, including Skype integration. If you're an Insider on the "fast" ring, you'll notice that the messenger's capabilities are now integrated with the native Messaging, Phone and Skype video apps for the platform. You'll also be able to reply to message notifications right from the action center. More importantly, if you're having trouble activating the free Windows 10 upgrade, this build fixes that up. Simply install this particular Preview release and use a Windows 7, 8 or 8.1 product key.