What happens when you right-click on an empty spot on your Desk Top?
Do you see the CCC option at the top of the context menu? If there is, click it.
If not, then is there an ATI icon in the System Tray? If there is, then right-click it.
If not, then is there an entry in your Program files Menu under the start button? If there is, then click it.
If none of the above, then check Device Manager. Is there a warning or disabled marker next to Display Adapters?
If so, completely uninstall the drivers. (ATI offers a driver cleanup utility on their site)
(I don't know anything about Driver Sweeper; call me paranoid, but I haven't had much good luck with driver management software.)
Check Device Manager again. If you still have warnings, then the drivers are not uninstalled correctly. Do it again.
Re-install the drivers and go through this list again.
FYI: Just in case you have a RAM Drive set up, don't let the installer put the extracted files there; I've had problems doing that.
Just extract to a folder of your choice on a real HDD- you can delete them later.
Still have problems? If so, post back here.
Hope this helps and Good Luck!