The image you see above is Microsoft's brand new logo. As you can see, it's clean, professional and features a windows-grid referencing Microsoft's most well-known product. It is meant to "signal the heritage but also signal the future — a newness and freshness."
Here's the previous Microsoft logo:
The company has gone through a number of logos over its 25 year history, including the "Heavy Metal" version from the 1980s you see below: