asp.net - Restrict user to delete file using C# -

hello guys trying make functionality in application user should not able delete file within folders , icons on desktop...till able user can't open folder when giving filesystemrights delete not working...how can achieve please me ....

here code..

     public string p = @"d:\\test";      public string sysloguser = system.security.principal.windowsidentity.getcurrent().name;      public void freezefile(string path, string user)     {           system.io.directoryinfo folderinfo = new system.io.directoryinfo(path);         directorysecurity foldersecurity = folderinfo.getaccesscontrol();         filesystemaccessrule rule = new filesystemaccessrule(user, filesystemrights.readdata, inheritanceflags.objectinherit, propagationflags.none, accesscontroltype.deny);          foldersecurity.addaccessrule(rule);         directory.setaccesscontrol(path, foldersecurity);     }     private void btn_action_click(object sender, eventargs e)     {         this.freezefile(p,sysloguser);         messagebox.show("permissions altered successfully");     }