Here is what I have for you, my relevant hardware is as follows:
Intel Core i5-3570K, clocked at 5.13 GHz, with integrated Intel HD 4000 graphics
Crossfire (two) Asus Radeon HD 7870 2GB
5 monitors, 3 of which driven by one amd card, 2 of which driven by integrated.
What's going on:
I had Windows 8 installed, and everything was happy. I then performed a clean install of Windows 8.1 the night of it's release. I left the drivers that were included for the HD 4000, and installed the latest stable versions from AMD for my 7870's. Everything still worked fine as of last night with all available updates from Windows installed. To fix a tearing issue in game with my 7870's, I installed the latest beta drivers for them from AMD, and now I am experiencing a problem where my HD 4000 powered displays do not work, and are not detected. Shortly, I am going to uninstall the beta drivers for the 7870's and repeat the special instructions to see if I can restore functionality.
UPDATE: I merely uninstalled AMD's beta driver, and re-installed the latest stable AMD driver, that's it, everything works again. I don't suppose this means it's now AMD's problem? Or is it incompatibility with Intel's driver as well? Please advise