To use the Android version of WhatsApp, either you need an Android phone or a well running Android emulator or SDK. There are so many emulators around, but I find BlueStacks App
Player a real treat. It is now available for free and one can install
the same on Windows PC, Laptops or Mac OS as well. It is a very smooth
emulator with full screen ability. You can install and run Android apps
from Google Play Store by signing up with existing Google Account.
YouWave is another
emulator for running Android applications on PC.