Wireless Keyboard doesn't work anymore with Bootcamp running under El Capitan
I have a mid-2011 21.5" iMac 2.7Ghz, 12 GB with a Bootcamp partition with Windows 8 installed on it.
Everything used to work just fine.
In late September / early October I installed El Capitan, but never checked Bootcamp as only a few client projects require me to switch platforms.
A recurring project which needs to be updated with Windows apps landed back on my desk today.
So I launched Bootcamp/Wiindows and everything looked normal.
My Apple Wireless Mouse works but found, when I got to the Windows account log-in screen, that my Apple Wireless Keyboard doesn't work with Windows anymore.
I've read several threads on this discussion board, and tried suggestions made by various people: resetting the VMRAM, turning the iMac off and disconnecting the power supply, pairing the keyboard with Bluetooth in Mac OS X again. But no joy.
Several responses seem to indicate that there is software that can be downloaded within Windows which enable the keyboard to work again.
However I can't get passed the log in screen to reach the Windows desktop, because I need to enter my security number or password using my wireless keyboard.
So I appear to be stuck between a rock and a hard place :-(
Does anyone have any sensible, bright ideas that I can try in order to resolve this issue?
iMac, OS X El Capitan (10.11.2), 21.5", 2.7 GHz Intel Core i5, 12GB