Your windows operating system or even your hard drive may be corrupted. Have you made any changes to the system like installations? You may need to do a system recovery just to fix the issue. Keep us posted if you need further informstion
Your system may suffering serious issues and it'll ask you to repair your computer before being able to use it further. Startup repair replaces or fixes corrupt system files and registries to make sure that you can use it without any hassles.
Try running startup repair 2 or 3 times to ensure that all the corrupt system files or registries has been replaced successfully.