I recently posted about having a problem detecting a second display. Here's the build I had:
Asus A88XM-A MB
2x4 GB Crucial Ballistix Sport RAM
120 GB Kindston V300 SSD
CoolMax V400w PSU
Installed Windows 7 with USB bootable drive and upgraded to 8.1
I went around and around with this build with no luck. I spent time on the horn with Asus, AMD, and Microsoft about this issue. I finally took the build back up to MicroCenter (where I bought most of the components) and decided to try a different motherboard. I popped in a Gigabyte F2A88XM-D3H board and problem solved. It immediately detected multiple displays. I have had no issues with the Catalyst drivers, the motherboard, or any other components since. I'm sure Asus has made a decent motherboard in the past but seeing as how this was my first build and the frustration I experienced with this, I think I may stick with Gigabyte from here out. Hope this helps someone out there who's pulling their hair out like I was, thinking it was a driver or a Windows issue.