Just bring up the task manager, Then click on the applications tab next to the processes tab. After that ,click on new task in the lower right corner and type
sfc /scannow and click ok. This will start the file protection process , which may take a while ,but it will be more then worth your time. Once it's done , it will ask you to insert the installation disk of your operating system , but don't worry if you don't have it , you don't really need to. Just click cancel when asked about the installation disk, and don't worry if it asks you about it again , it's weird like that. Then just bring up windows task manager if it isn't open already, and click on shutdown , and from there click on restart in the list it brings up. Glad I was able to help you, and good luck! Let me know if there's anything you don't understand.