This is the start of a blog series on the latest operating system from Microsoft. Today is the first day I’ve used it, so keep following my daily updates on what happens on my adventure into Windows 10. Today is a big day for tech bloggers. Microsoft just released Windows 10 as a free upgrade to owners of either Windows 7, 8, or 8.1 operating system. If you haven’t yet upgraded, you can do so by visiting Windows Update, or by downloading the upgrade directly from Microsoft.