How to Repair windows 8 without losing files

When to run this: You think that your system is very slow
                           Infected with virus
                         
                         
step 1: Turn on windows8
step 2: Click on Desktop app
step 3: Press F3 button on keyboard
step 4: Now you can see Settings option
step 5: click on settings
step 6: Now you can see Refresh your PC
step 7: Click on Refresh your PC
step 8: Now you can see window
step 9: Click on next
step 10: Now you can see Ready to refresh your PC message, Click on Refresh

Wait few min until Restart
After restart

You can see a window: Getting Device Ready

Again it will Restart