1. Just open https://web.whatsapp.com/ [Use Google Chrome web browser only] from your Computer.
2. Keep cell phone connected with internet and open Whats App
3. Select option ‘Whats App Web’ from the menu [from cell phone] (If this option does not appear, then update Whats App)
4. Select “OK Got it” on your Mobile and your cell phone camera will be activated
5. Now scan the QR code appearing on PC screen with cell phone camera activated as above.
Now Whats App will be available on PC screen also.
(CA. Tejas K. Andharia -B. COM, F.C.A., D.I.S.A.(ICAI), D.I.R.M.(ICAI), Bhavnagar, Gujarat, email@example.com)