Click the power button on your Start Menu
Press the Shift Key and click Restart
Your PC will boot into the Windows Recovery Environment
Go to Troubleshoot - Advanced Options - Command Prompt
Type this command and press Enter:
chkdsk C: /f /r
Wait for that command to complete, run this command 3 times, one at a time.
chkntfs /x c:
Type this command and press Enter:
fsutil dirty query c:
What is returned from that command?