Getting the error message after changing Graphic card

Hi,
I installed ATI Radeon HD 4600 on my machine running with Windows 7 64-bit operating system. After that, I received an error message (application error). I clicked on OK but no permanent solution. How can I get a remedy of this issue?
Please help.

dustforce.exe – Application Error
The application was unable to start correctly (0x000007b). Click OK to close the application.
