Close internet connection.
Uninstall anything in device manager that shows a yellow triangle (check to delete software as well if prompted), and press "scan for hardware changes"
Repeat this process until windows installs only basic drivers.
Keep internet connection disabled
Then, try to clean install the latest supported catalyst software.
Make sure you run the installer as an administrator.
If you do it right and still fail, reinstall windows and try again.
gigabyte X58A-UD3R rev.2, core i7 975 3.9ghz (stock voltage), windows 8.1 64-bit, corsair 12gb DDR3 1600mhz 7-7-7-20 RAM, sapphire HD 6990 (stock clocks), coolermaster ultimate 900w PSU.
amd catalyst 14.6 RC2 june23