I had all 4 displays connected and working fine this morning, then I tried to move one of the monitors to the other side of the desk and everything is now completely screwed up.
Here's what the state is right now. I have the desktop duplicated on displays 1 (laptop screen) and 4 (monitor I'm trying to move), and extended to 2 and 3 (monitors already connected).
If I select "Extend desktop on 1 and 4" and try to apply, it says it can't save the configuration:
If I then try to make any changes to display 4 or click "detect", explorer crashes, then when it restarts the configuration is back to the original above.
I can select "Show desktop only on 1", in which case monitor 4 shuts off and I have a good configuration between 1, 2, and 3:
But If I try to then select Monitor 4 and select "Extend desktop to this display" the dropdown just instantly reverts back to "Disconnect this display"
As I said, these 4 monitors were working just fine this morning. But for some reason when I disconnected the 4th monitor and tried to reconnect it, everything broke. I have rebooted to no avail.
Edit: I also just discovered that the previews of windows when I press Alt+Tab is no longer working. I just get icons. I can't capture a screenshot of this.
Edit 2: Here's the information about my graphics card:
AMD FirePro M6100 FireGL V
Display 2 is connected via display port, display 3 via DVI, display 4 via VGA. All are connected by a docking station, not directly to the laptop (Dell Precision M6800)