Have you been looking for the definitive review of Windows Phone 7? Well, look no further. Microsoft's next (and perhaps final) opportunity to break back into the smartphone race has officially begun, and Engadget has been cranking on a variety of launch devices across several continents to see if the platform holds water.

Back in July we took a deep dive on Windows Phone 7 using a developer device that Microsoft handed out to journalists, and now we're back for the full review. What we realized going into this process was that really very little had changed between the summertime preview and the new OS' fall launch. Even though there have been tweaks and fixes in Microsoft's mobile experience, there hasn't been any addition so large that we felt the software required a completely fresh look. Instead, what we needed to do was go back to the observations made during our initial experience with the OS, compare it to the final product, and figure out where the company improved (or diminished) specific facets of the operating system. And of course, we finally had a real chance to use Xbox Live and third party applications -- two of the crucial elements of this OS. So, below is our re-edited, refreshed take on Windows Phone 7, complete with real answers to nagging questions, and our definitive score of Microsoft's great smartphone hope at version 1.0. Read on for the full story!