Код: Выделить всё
DirectoryInfo d1 = new DirectoryInfo(Path.Combine(RuntimeEnvironment.GetRuntimeDirectory(), "Temporary ASP.NET Files"));
DirectorySecurity md1 = d1.GetAccessControl();
string user_1 = fa.TextGuestDomain + "\\" + fa.TextGuestUser;
md1.AddAccessRule(new FileSystemAccessRule(user_1, FileSystemRights.FullControl,InheritanceFlags.ObjectInherit,PropagationFlags.InheritOnly, AccessControlType.Allow));
d1.SetAccessControl(md1);
Подробнее здесь: https://stackoverflow.com/questions/609 ... lders-in-c