Because you are saying that you got the problem 4 times every time you reboot, I suspect it is the same case as the forum post in the beginning. That guy solved the problem by installing the Display drivers AFTER installing KB888111, therefore I suggest reinstalling/ upgrading the current...
That's alright. Everyone was a noob before they become a pro.
Did you install KB888111 before installing Realtek driver? KB888111 should be installed first.
You could try to reinstall Realtek to see if this is the case
Are you saying that if you listen through the USB headset, there's no problem; but if you try to listen with onboard sound, you could not hear anything?
However, some people buy macs because of its brand name.
IMO, if you are willing to invest on an external graphics device like this, then you are willing to play games. And most games comes on Windows