GlobalKeyboardHookLocalSupression

 public partial class Form1 : Form
    {
        readonly GlobalKeyboardHook _globalKeyboardHook = new GlobalKeyboardHook();

        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            _globalKeyboardHook.HookedKeys.Add(Keys.LShiftKey);
            _globalKeyboardHook.HookedKeys.Add(Keys.RShiftKey);
            _globalKeyboardHook.HookedKeys.Add(Keys.LControlKey);
            _globalKeyboardHook.HookedKeys.Add(Keys.RControlKey);
            _globalKeyboardHook.KeyDown += GlobalKeyboardHook_KeyDown;
            _globalKeyboardHook.KeyUp += GlobalKeyboardHook_KeyUp;
        }

        void GlobalKeyboardHook_KeyUp(object sender, KeyEventArgs e)
        {
            lstLog.Items.Add("Up\t" + e.KeyCode);
            //e.Handled = true; //if set to true, the key is supressed globally, i only need to supress for this and children
        }

        void GlobalKeyboardHook_KeyDown(object sender, KeyEventArgs e)
        {
            lstLog.Items.Add("Down\t" + e.KeyCode);
            //e.Handled = true; //if set to true, the key is supressed globally, i only need to supress for this and children
        }

        protected override void OnKeyDown(KeyEventArgs e)
        {
            switch (e.KeyValue)
            {
                case 16:
                case 17:
                    MessageBox.Show("Shift and control keys aren't allowed in focus",
                                   "Error",
                                   MessageBoxButtons.OK,
                                   MessageBoxIcon.Information);
                    e.Handled = true;
                    break;
                default:
                    base.OnKeyDown(e);
                    break;
            }
        }
    }