I have doubt in directory undeletable concept. In Windows operation system, we convert a Undeletable file or folder in to deletable by using the command as "cacls FolderName /e /c /g %username%:f". I used the same command to access the "Undeletable folders" (for example Recovery, Documents and Settings etc.,), which is present in the C: drive. It doesn't work. How they create this kind of folders. If any other ways to do this. Kindly clear me. Thanks in advance.
Those folders have the "list folder/read data" permission set to deny for everyone. Deny takes precedence over allow, so it doesn't matter what permissions you give to a user: the deny setting will overrule it. You have to remove that setting first, which probably means you also have to take ownership first. They're owned by SYSTEM.