Excellent tutorial, step-by-step with screen-shots, how-to run Android on your computer with Android Emulator from Google.
HOW-TO GEEK TUTORIALAndroid Emulator
-from How-To Geek
"...easy way to run Android on your Windows, Mac, or Linux computer. Google provides an Android emulator with their SDK, which is designed to let developers test their apps on Android before running them on handsets. We can use this to test drive Android on our computer, here’s how to do it. ..."
How to Test Drive Google Android on Your PC Without Buying a Phone
Android SDK: http://developer.android.com/sdk/index.html
Run Android on Your Windows Mobile Phone