You're missing the point with your answer.
Your point (1). The microphone was working fine without any need to mess about with the BIOS, then it suddenly stopped working ONLY with Day Z.
But it's no matter now as the Voicemeeter Banana Advanced Mixer I linked in my previous answer has solved the problem, without the need to mess about with the BIOS for one game that has suddenly stopped working.

Hey guys, I found a solution to the problem, which may help you out.
No thanks to BI or Microsoft. Someone suggested I try using Voicemeeter banana mixer, and it solved the problem.

Come on give me some help please.
I have now reinstalled both Steam and DayZ, but it's still not working.
I have tried this with two different headsets, a camcorder and a jack mic, which all work in everything but still no VOIP in DayZ.

Any news on this?
Any ideas how I can find more info on the problem?
Any chance of actually getting any support from you company for a bug that is ruining the whole game experience for me?
Any chance you actually care about your paying customers that you will actually respond to me at all?