Easy steps to repair Windows 8
1. Press F8 while booting the system to go into Windows Recovery Menu. Then click on the Troubleshoot.
2. Next, Click on Advanced options to get into Automatic Repair menu
3. Next, Click on Automatic Repair.
4. Next, Select the account.
5. Enter the password in next screen.
6. Next, Windows will search for problem and will correct automatically. If problem still persist then you may have to re-install your Windows 8.