I’ll consider this as a simple task. What you have to do is just download and install the BlueStacks App Player.
For anyone who doesn’t know what is it, BlueStacks is just an Android
app player, a Virtual Machine wrapped for your PC (or Mac) with which
you can run from games to regular apps, for Smartphones and/or tablets.
App Stores
After you finish installing it what you have to do is downloading and
installing WhatsApp right? But, to accomplish it from any Android
Smartphone or Tablet, normally you go to the Play Store and then you
search for WhatsApp and after you download and install it. Yeah. pretty
the same thing, but here you do not have the Play Store :)
Having it means you have been certified from Google, but hey BlueStacks
is not a Smartphone or Tablet, so they have to fill the gap, and this
is totally done by their 1Mobile Store. You can find it by clicking on
“App Stores” on top and after that 1Mobile app.
Download, Install and Configure WhatsApp
So, you opened 1Mobile app store and you found that is pretty similar to Play Store yeah? You’re right :)
Go fire the search button in the top-right corner of BlueStacks screen
and write inside “WhatsApp” and press Enter. You’ll be returned with a
list of apps matching that name, inside of if you’ll find Whatsapp,
click on it and then click the Download button.