How to Repair Windows 10 without a CD

1. Open Start.
2. Search for Create a restore point, and click the top result to open the System Properties experience.
3. Click the System Restore button.
   
   
4. Click the Next button.
   
   
5. Select the restore point that you want to use on your computer.
6. Click the Scan for affected programs button to understand the apps that will no longer be available because they’re added after the creation of the restore point.
   
   
7. Click the Close button.
8. Click the Next button.
9. Click the Finish button.
   
   
   
   

Once you complete the steps, System Restore will return your computer to the previous working state.

Using these methods, you can successfully repair your copy of Windows 10.