Duplicate Folders

Thanks for prev answers – 100% success
I also have the following folders in Docs and Settings:
All Users
All Users.WINDOWS
Default Users
Default Users.WINDOWS
LocalServices
LocalServices. NT AUTHORITY
NetworkServices
NetworkServicesNT AUTHORITY

Q1 – Which Folders should I delete
Q2 – How do I delete them – I have tried to delete All Users.WINDOWS but system says files are required by Windows System