I think this will help
Press CTRL+ALT+DEL
Click Task Manager
Click File then New Task
Type msconfig
Click on tools and then Launch Command Prompt
Type CHKDSK /r /f then Hit Y after confirmation prompted
After that, type sfc /scannow and wait 'til scan has finished
After scan has finished reboot your PC and wait 'til chkdsk has finished scanning and repairing
PS: I think your sfc /scannow didn't helped you because your cmd is not running as admin
If symptoms persist Consult A Doctor :P