try something like (did not test, so do not know if it works)using System.DirectoryServices;
using System.Runtime.InteropServices;
using System;string strNodeName = "YourUserNameToDelete";
DirectoryEntry User;DirectoryEntry AD = new DirectoryEntry("WinNT://" + Environment.MachineName + ",computer", ".\\administrator", "adminPasswor");try
{
    User = AD.Children.Find(strNodeName, "User");
    AD.Children.Remove(User);
}
catch(COMException cex)
{
    Console.WriteLine(cex.Message);
}AD.Close();