Hi Petrossa,
I am not so stupid that I would have tried to run the 64-bit installer on a 32-bit OS - I've been "playing" with computers since the days of CPM and DOS2.0, have gone through all the iterations of windows and also toyed wiith OS/2 for a while.
While I appreciate the benefits of 64-bit architecture, I really do not want the b@ll-ache of having to rebuild the machine and reinstall all the apps that are in use, some of which won't run on 64-bit so I'd have to install a VM to run them.
If WhatsApp has released a 32-bit installer then it should work and they would be helping the user community by having a little bit of support out there.