You need to uninstall the beta of Service Pack 1 before you install the final release. Here’s how you do that:
1.- Click Start | Control Panel | Programs and Features (if you’re not in Classic view, this is in the Programs category).
2.- Click View Installed Updates.
3.- On the Uninstall an Update page, click “Service Pack for Microsoft Windows (KB 976932)
4.- Click Uninstall.
Follow the instructions to remove the beta from your machine.