states you must have a device meeting these minimum specifications: Whatsapp Messenger.cab For Htc Windows Mobile 6.1
For users of HTC devices during the late 2000s, software was typically installed using CAB (Cabinet) files
However, the service itself is a ghost. You will see the familiar icon, the splash screen, and perhaps even the contact list UI—but the green light will never turn blue.
The problem with finding a WhatsApp ".CAB" for Windows Mobile 6.1 today is that you are trying to install a 2024 engine into a 2008 car.