A short video: Install and run WhatsApp on Computer, Windows 7 based laptop or PC, using the latest updated BlueStacks (june 2013). More detail info : goo.gl/eqk6N
WhatsApp will run on Windows 7 PC though BlueStacks. BlueStacks emulated android phone devices (which is required by WhatsApp) on Computer Windows PC and Mac OS. During installation, WhatsApp will send 6 digit code by SMS or Phone call to our number. That's why a valid phone number is required.
Latest BlueStacks come with a new UI, which also require us to setup 1-click sync (one time setup) before we can download apps.