Upgraded to Windows 10, amongst other problems the chief one was that my R9 200 was not letting me extend to my three Dekk s2340Ls. Three would be there, but I could only use two and when I tried to extend it to the third one it said:
to extend a desktop, a desktop or display must be disabled
As I couldn't resolve this, I decided to revert back to Windows 8.1 which has been working fine on this machine for 9 months. Same problem. Elected to System Restore to default, erasing apps. Reinstalled CCC, same issue. It is not particular about which monitor it can't see, if I unplug one of the working ones, the dead one will work. I am running DVI to HDMI using an adapter for two of them, HDMI for the third. Doesn't matter which combination I try. Was maybe guessing new version of CCC might be it, but I can't see where I can get an older version to try. The resolution is also a lot worse than it was before. I am on the latest driver, 15.200.1062.1003.
Please let me know if you need anything else from me, I really want my old PC/look back.