Yesterday AMD released a new Beta 14.6 driver, and it became apparent rather fast that Windows 8.0 was not supported. Initially I figured this to be a mistake in the installer, but AMD is doing this deliberately. Starting from AMD Catalyst driver version 14.6 AMD will no longer support Windows 8.0.
This means you are forced to upgrade towards Windows 8.1, as that build is supported. We have to say that it is a pretty bold move to force end-users towards a new Windows build.
To use the latest version of Catalyst, you'll need Microsoft's free update to Windows 8.1, which is available through the Windows Store. (Older desktop-only versions of Windows should also be fine.) In a statement, the company said it chose to “focus our development efforts on the latest version of Windows 8, which is available to all users as a free update.” AMD's decision to end Windows 8.0 support shouldn't be a problem for most users. It however can be an issue for enterprise users who aren't allowed to update their own computers, but we're guessing most of those machines aren't running Watch Dogs.
The latest usage share statistics from Netmarketshare show that a little more than half of Windows 8 machines are running version 8.0, while a little less than half are running Windows 8.1.