I'm still having difficulty getting this to work. I'll state precisely what I did as clearly as I can so I can receive the proper help.
I'm using rMBP 13 (2015). I have the ISO Windows 10 on a USB. I ran bootcamp with USB plugged in and followed the instructions. During installation I get stuck on the Realtek audio prompt within Windows 10 operating system as OP has mentioned.
I followed the steps which was mentioned as a solution from within Windows 10:
I go to "OSXRESERVED (D:) > BootCamp > Drivers > RealTek" folder and do the realtek setup.
Then I go to task manager and force quit the stalled bootcamp installation promp.
I do a computer restart.
I then go back to "OSXRESERVED (D:) > BootCamp > Drivers" and select Setup.
During the bootcamp installation it still gets stuck at the RealTek part. I also got some sort of error that had to do with Bluetooth but I clicked ok.
I don't know what I'm doing wrong so if someone could please help me as precisely as possible I would truly appreciate it.
In sum, within Windows 10 operating system while bootcamp is trying to install, I'm stuck on the RealTek portion. I tried the steps mentioned but it doesn't work.