I've tried all kinds of things including re-installing the Broadcom Wireless ac driver to no avail using the Boot Camp Support Software 5.0.5033. No avail. I know the wireless adapter works because I connected to internet on OS X.
I'm beginning to think that Windows 8.1 early adopters on Macs are screwed.
I'm beginning to think that Windows 8.1 early adopters on Macs are screwed.