How to get list of windows user in C#

If you want to have the list of an specific windows group in C# you can get this list by these lines of code below. Notice that you have to add a reference to System.DirectoryServices .

DirectoryEntry localMachine = new DirectoryEntry("WinNT://" + Environment.MachineName);
DirectoryEntry admGroup = localMachine.Children.Find("administrators","group");
object members = admGroup.Invoke("members", null);
foreach (object groupMember in (IEnumerable)members)
{
    DirectoryEntry member = new DirectoryEntry(groupMember);
    lstUsers.Items.Add(member.Name);
}

you can download the source code here:
http://www.tabatabaei.info/csharpsamples/WindowsGroupMember.rar