Hello. I am using VB.net 2002. I have facing a problem with the datagrid. I want to disable the delete key when the cursor is in a cell in a New Row. How do i do that? I have tried overriding the Processcmdkey function, but still it automatically adds a new row when the delete key is pressed. I have tried the key_up and key_down events as well. How do I solve this problem? Please help. Thanks.

Here's a discussion that gives a few different options:
http://dotnet247.com/247reference/msgs/50/250024.aspx

One way that I've done similar things in the past is make a class that derives from NativeWindow, hook into the datagridtextbox's wndproc, and catch/cancel the event from there. It's not a trivial task and may be overkill for this. When I did it, the purpose was to catch paste messages into a certain column so I could do some processing on the data before it was pasted.

Here's the native code class I wrote:
    /// <summary>
    /// Raises an event when a control receives a paste message
    /// </summary>
    public class PasteListener: NativeWindow
    {
        /* usage:
         * 1. create a new instance of this object, sending the constructor the control you want to
         * watch for a paste event: PasteListener pl = new PasteListener(this.textbox1);
         * You have to have one pastelistener for each control, so you may need to create a structure to
         * hold them.
         * 2. Add your own event handler to handle the paste event:
         * pl.Paste += new PasteListener.PasteEventHandler(this.DetectPaste);
         * */
        private const int WM_PASTE = 0x0302;
        public Control myControl;

        public delegate void PasteEventHandler(object sender, CancelEventArgs e);
        public event PasteEventHandler Paste;

        public PasteListener(Control control)
        {
            control.HandleCreated += new EventHandler(this.OnHandleCreated);
            control.HandleDestroyed += new EventHandler(this.OnHandleDestroyed);
            this.myControl = control;
        }

        // Listen for the control's window creation and then hook into it.
        internal void OnHandleCreated(object sender, EventArgs e)
        {
            // Window is now created, assign handle to NativeWindow.
            AssignHandle(((Control)sender).Handle);
        }
        internal void OnHandleDestroyed(object sender, EventArgs e)
        {
            // Window was destroyed, release hook.
            ReleaseHandle();
        }

        protected override void WndProc(ref Message m)
        {
            // Listen for paste messages
            switch (m.Msg)
            {
                case WM_PASTE:
                {
                    CancelEventArgs ce = new CancelEventArgs();
                    OnPaste(ce);

                    if (ce.Cancel)
                        base.WndProc(ref m);

                    break;
                }
                default:
                {
                    base.WndProc(ref m);
                    break;
                }
            }
        }

        protected void OnPaste(CancelEventArgs e)
        {
            if (Paste != null)
                Paste(this, e);
        }

        public Control Control
        {
            get { return myControl; }
        }
    }

And here's the DataGrid.ControlAdded event handler - where you actually hook up the NativeWindow to the datagridtextbox:
        private void Control_Added(object sender, System.Windows.Forms.ControlEventArgs e)
        {
            if (pnCol.TextBox == e.Control && this.MaterialPasteListener == null)
            {
                this.MaterialPasteListener = new PasteListener(e.Control);
                this.MaterialPasteListener.Paste += new PasteListener.PasteEventHandler(this.DetectPaste);
            }
        }

Good luck,
-SN