The current requirements for Whatsapp seem to be Windows 8 or higher or Mac OS X 10.10 or higher and Firefox 60 or higher, no mention of supporting Linux.
If your OS is supported then you need to update a more recent Firefox version, otherwise you need to update to a newer Windows version or you can consider to switch to a Linux distribution that supports your hardware.
The current requirements for Whatsapp seem to be Windows 8 or higher or Mac OS X 10.10 or higher and Firefox 60 or higher, no mention of supporting Linux.
If your OS is supported then you need to update a more recent Firefox version, otherwise you need to update to a newer Windows version or you can consider to switch to a Linux distribution that supports your hardware.
*https://www.whatsapp.com/download
*https://web.whatsapp.com/
