It has to do with Microsoft's .NET Framework Version 2.0.50727 which is required to run ATI's catalyst software. Go to ATI's support site and download the driver for your card, NOT the Catalyst software (you have options for both). Uninstall your current ATI driver, restart and then run the software you just downloaded. Also, uninstall any .NET Framwork versions 2.0 and higher. Thought this would help since I had the same problem message.
Poi ho letto altrove, insomma, a quanto dice la gente basta che installi i driver senza l'ATI CCC (Control center??!?! Non so che nn ho mai avuto ATI) e funge tutto.