1. Click the 'Start' button and then click the 'All Programs' icon.
2. Click the 'Accessories' button and then right-click on the 'Command Prompt' icon.

3. Click the 'Run as Administrator' option from the menu, then enter your administrator password into the field that appears.
4. Type 'sfc /scannow' into the command prompt and press the 'Enter' button.
5. Wait for the scan to complete and then restart your computer to clear the error.