Also, if the above and nothing else helps, you could eventually try this crazy stunt: Uninstall the driver, ccc etc. and pull out your ATi card, swap it with the old nVidia one. Then install the nVidia driver to make it the primary device. Then uninstall it, swap again and install CCC and the ATi driver again.
Also make sure not to confuse the x64 and x86 version
Oh and one more thing: if you got a fast internet connection you could try this: Install the Crashplan backup software. It comes with a 30 day "cloud backup trial".
http://www.crashplan.com/consumer/download.html
So let's say if it takes you 2 weeks to upload all your stuff from your system drive you still have 2 weeks to download it again after you re-install your system.
You can ask their live support staff about the procedure:
https://crashplan.zendesk.com/accoun.../chat/orTicket
Might help