If you do a search on your pc, you can not see any protected system files in the search result. Because Protected System files are configured not to display by default. They are important files. If something happened to these files system won’t work properly.
How to check for problems with protected system files ?
Open “Run” and run this command “SFC.EXE /SCANNOW” (without invited commas)
And it will ask you the windows cd
If there is any corruption in protected system files windows will repair them.