[DllImport("kernel32.dll")]
        static extern uint GetCurrentThreadId();

        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        private static extern int CallNextHookEx(int idHook, int nCode, IntPtr wParam, IntPtr lParam);

        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        private static extern bool UnhookWindowsHookEx(int idHook);

        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        private static extern int SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hInstance, int threadId);

        [DllImport("user32.dll")]
        private static extern bool SetDlgItemText(IntPtr hWnd, int nIDDlgItem, string lpString);

        delegate int HookProc(int nCode, IntPtr wParam, IntPtr lParam);

        static HookProc dlgHookProc;

        private const long WH_CBT = 5;
        private const long HCBT_ACTIVATE = 5;

        private const int ID_BUT_OK = 1;
        private const int ID_BUT_CANCEL = 2;
        private const int ID_BUT_ABORT = 3;
        private const int ID_BUT_RETRY = 4;
        private const int ID_BUT_IGNORE = 5;
        private const int ID_BUT_YES = 6;
        private const int ID_BUT_NO = 7;

        private const string BUT_OK = "Save";
        private const string BUT_CANCEL = "Cancel";
        private const string BUT_ABORT = "Stop";
        private const string BUT_RETRY = "Continue";
        private const string BUT_IGNORE = "Ignore";
        private const string BUT_YES = "Yeeh";
        private const string BUT_NO = "Never";

        private static int _hook = 0;

        private static int DialogHookProc(int nCode, IntPtr wParam, IntPtr lParam)
        {
            if (nCode < 0)
            {
                return CallNextHookEx(_hook, nCode, wParam, lParam);
            }

            if (nCode == HCBT_ACTIVATE)
            {
                SetDlgItemText(wParam, ID_BUT_OK, BUT_OK);
                SetDlgItemText(wParam, ID_BUT_CANCEL, BUT_CANCEL);
                SetDlgItemText(wParam, ID_BUT_ABORT, BUT_ABORT);
                SetDlgItemText(wParam, ID_BUT_RETRY, BUT_RETRY);
                SetDlgItemText(wParam, ID_BUT_IGNORE, BUT_IGNORE);
                SetDlgItemText(wParam, ID_BUT_YES, BUT_YES);
                SetDlgItemText(wParam, ID_BUT_NO, BUT_NO);
            }

            return CallNextHookEx(_hook, nCode, wParam, lParam);
        }

        private void Button_Click(object sender, EventArgs e)
        {
            dlgHookProc = new HookProc(DialogHookProc);

            _hook = SetWindowsHookEx((int)WH_CBT, dlgHookProc, (IntPtr)0, (int)GetCurrentThreadId());

            DialogResult dlgEmptyCheck = MessageBox.Show("Text", "Caption", MessageBoxButtons.AbortRetryIgnore, MessageBoxIcon.Exclamation, MessageBoxDefaultButton.Button3);

            if (dlgEmptyCheck == DialogResult.Abort)
            {

            }

            UnhookWindowsHookEx(_hook);
        }

Custom MessageBox Buttons

c

C#