Hi Dave
The AMD Catalyst Install Manager is designed to install the Drivers for the AMD graphics device.
The AMD VISION Engine Control Center replaces the Catalyst Control Center on systems with an AMD CPU.
It doesn't matter how the drivers or utilities are installed, the results will be the same.
If you did not specifically install the AMD driver from the AMD website, then the driver may have been installed by Windows Update. You can check this by checking the Installed Updates option in Windows Update.
Regards