I've been attempting to troubleshoot a 2012 Mac Pro with a Windows 7 64-bit Bootcamp partition to no avail, and I need some help. One of the three 27" LED Cinema displays I have connected works perfectly fine on the OS X partition, but only offers the resolutions 1280x720 and 800x600 on the Windows partition. The standard resolution for one of these displays is 2560x1440. The display that is having issues is connected to a Mini Displayport to Dual-link DVI adapter (Atlona AT-DP400), but because the monitor is in full resolution on the OS X partition, I do not believe this is the issue.
I tried to access the Catalyst Control Center in Windows to adjust the monitor's resolution, but I get an error message saying that there are no settings that can be changed. Twice I have completely uninstalled AMD Install Manager, deleted any ATI/AMD folders in the Program Files and Program Files (x86) folders, cleaned the registry, and reinstalled the latest AMD Bootcamp drivers (15.201). However, if I attempt to open Catalyst Control Center, I continue to get a message that there are no settings that can be changed. Here are the relevant system specs:
AMD Graphics Card
Radeon HD 5870
Windows 7 64-bit (Bootcamp)
Driver version installed
Bootcamp driver 15.210
2x Apple 27" LED Cinema
1x Apple 27" LED Cinema connected via Atlona AT-DP400
I would appreciate any suggestions to help me resolve this problem. Thank you for your time!