Here our ways with two methods thats with help of blue stack and without bluestack.
Download Whatsapp for PC Free With BlueStack
Download Whatsapp For PC Free Without Bluestack
Bluestack is the type of android emulator you can use other android type of android emulator in this way you can avoid using bluestack also bluestack has some cons as it would not fast like this emulator.
Install this software in your windows PC.
Click on the view icon showing at the left top and on the dropdown menu click on the online content.
After view comes click on the whatsapp and this will be installed in few minutes.
You can see installed app in your PC android emulator.
Now follow the procedure as like in first method after you install whatsapp. Now you whatsapp is ready use in your PC.