Okay, since you've got warnings, I'd recommend uninstalling it and then installing the latest version. To effectively uninstall AMD/ATI drivers, once you've downloaded the latest AMD/ATI drivers, launch the new driver exe, and rather than clicking Install, click Uninstall, and go through the uninstall process. Once that's done, restart, and then do the same, but this time click 'Install'.
Edit: Okay, since you're having that issue consistently, I'd give Driver Sweeper
a try. Once downloaded and installed, uninstall your current AMD/ATI drivers, boot into safe mode and run it. Delete any leftover AMD/ATI library files. After you've done that, install the latest AMD/ATI drivers in Windows (normal mode, not safe) again.