I have experienced similar problems as described above when updating from an older CCC (Ver. 8) to the current release. I desperation, I re-installed Ver 8, overwriting 'older' files when prompted. Once determining that CCC was working again, I checked the ATI directory and found that there is an 'Uninstall' subdirectory containing the uninstall executable. The result is a clean removal of CCC, the new release then installed correctly. I hope this helps.