Type “ sfc /scannow” without quotes and hit.Start button, click on Command Prompt (Admin). System File Checker is a utility in Windows that allows users to scan for corruptions in Windows system files and restore corrupted files. I suggest you to perform the below troubleshooting steps and check. This issue might be due to corrupted or missing System files. I understand the inconvenience that you are unable to access notification and action center on your computer, we will help you to resolve this issue. We appreciate your interest in Windows 10. Thank you for posting in Microsoft Community.