I would head for device manager and uninstall all the installed drivers for keyboards .
turn the pc off and reboot with the Blackwidow plugged in
Hopefully windows will reload a fresh driver and all will be good
I did as you suggested, and when the pc rebooted, the keyboard worked fine for about 10 seconds until the little popped up that stated 'drivers had been installed' then the problems came back. What i ended up doing is downloading the legacy drivers, back before synapse was required. All is well now. Thanks for your help