No sound, Windows 10, 2012 MBP, latest boot camp

I have a 2012 MacBook Pro, and have just installed Windows 10 and the boot camp drivers. Everything works great besides a lack of audio. Device manager says latest drivers are installed even thought there is an exclamation mark saying the device cannot start, bootcamp installer completes successfully, and installing latest Realtek audio drivers does nothing. Boot camp has been updated to support my model and Windows version. Many people have this problem, but I haven't been able to find a fix.

Any ideas?