If you like to try out this new mobile operating system on your Windows computer, here is a brief and precise tutorial with screenshots.
- Download and unzip the Android SDK. Run the SDK Setup exe file, then select Available Packages option shown on the left column (see screenshot). 
- Now expand ‘Sties, Packages and Archives’ from the right column and select SDK Platform Android 2.2, API 8, revision 1. Then click Install Selected button. 
- After finishing the download, select Virtual Devices option from the left column and click on the New button. Enter a name for your virtual device and choose the Android 2.2 package from the Target drop-down list and click on the Create AVD button. 
- Now you can see your new Android device, running 2.2 in the main Virtual Devices panel (see screen-shot above). Select it, and click on Start to launch the new OS. 
In my system, it takes few times to fully load. However, it was a good experience to try out this new Android 2.2 (Froyo) OS on my Windows.