Windroy (WindowsAndroid) is a project that combines the functions of YouWave and Bluestacks, and attempts to emulate Android in Windows. Its aim is to be able to run all Android apps, and to be as easy to use as any other Windows application.
Android 4.0.3 is the version that currently runs in WindowsAndroid. It's quick to start, and offers you a basic Android experience, which has some drawbacks.
In WindowsAndroid, you won't find Google Play, the Android's app store. To run applications, you have to download the APK file, and put it the SocketeQ\windowsandroid_root\system\ folder.
WindowsAndroid also lacks audio at the moment, and the web browser is unstable. However, it is a new project, and these problems should be ironed out as it develops. It's also a neat way to discover the ins and outs of Android.
WindowsAndroid is still very young. It's a promising project to get Android running in Windows, but at the moment its far from perfect.