I am running duel boot Win 7 Hp 64 bit and Win 10 tech preview Build 9879.
When switching between O/S. I Have just noticed today that when coming out of win 7 and entering the selection screen my Key board does not work and I have to wait for the time out selection(win7 is set to prefered) then shut down the pc, switch on and all is fine again.

I know about the delay response time problems(next build fix) but anyone else had this new to me problem?.
Ps key board is wireless logitec Mk320 but worked fine untill today.