sentences:  ), protecting them from deletion or from replacement by older versions.The digital signatures of these files are checked using code signing and the signature catalog files stored in the %Systemroot%\system32\CatRoot\{F750E6C3-38EE-11D1-85E5-00C04FC295EE} folder.Only certain operating system components such as the "Package Installer" (Update.exe) or Windows Installer (Msiexec.exe) can replace these files.