I had a similar problem on Windows 8 (should be the same fix on 7) and finally figured it out.
1. Hit start and search for device install and click "Change device installation settings."
2. Click the box beside "No, let me choose what to do."
3. Click the box beside "Never install driver software from Windows Update."
4. Save Changes.
Go here http://support.amd.com/us/kbarticles/Pages/AMDCatalyst1...
and download the AMD Mobility Catalyst Beta for Windows.
Install it and let your computer restart.