There have been some problems with downloading Windows 7 and graphics cards. I went to Diamonds website and, I don't see anything for Windows 7 so, what I suggest you do is uninstall your AMD software and reinstall at AMD's website. Go to your programs and featuers and right click on ATI Catalyst install manager. Right click on that and click next in window taht comes up. You will get a window with selections. Chek the box next to Express uninstall remove all ATI software and click next. Allow and click next, etc. till finished. Then, if not prompted, restart. When your system comes back up, go back to device manager and make sure all ATI is uninstalled. There might be a catalyst 2, etc. Go to AMD's website;
http://support.amd.com/us/Pages/AMDSupportHub.aspx
1 Componenet catagory-click on arrow at right, click on and select "Desktop graphics"
2 Product line- "Radeon HD Series
3 Product model-Radeon HD 6xxx series PCIe
Then choose your operating system Win 7, 32 or 64
Click view results. You will want to select the first download. Click on and allow to run.
When it gets to a window with a selection of custom or express install click on express.
Allow to finish and restart. You should be all set.