HIT ENTER SUBMIT FORM WINDOW FORM C#

You can set AcceptButton[^] property to the button in your Form what handles the data entered.

As SA has pointed out, AcceptButton property makes sense when used with form1.ShowDialog(). And remember, just setting the AcceptButton/CancelButton is not enough. This just tell which button should be invoked on ENTER/ESC. We have to set the DialogResult in the Button handler.

button1.DialogResult = System.Windows.Forms.DialogResult.OK;
button2.DialogResult = System.Windows.Forms.DialogResult.Cancel;

form1.AcceptButton = button1;
form1.CancelButton = button2;

You can set form1.KeyPreview = true; and handle event form1.KeyDown.
Setting KeyPreview to true, then the form will receive key events before the event is passed to the control that has focus

form1.KeyPreview = true;
form1.KeyDown += new System.Windows.Forms.KeyEventHandler(this.form1_KeyDown);

Method to suppress ENTER button.

private void form1_KeyDown(object sender, KeyEventArgs e)
{
  if (e.KeyData == Keys.Enter)
  {
    e.SuppressKeyPress = true; // Event should not be sent to the control
    SaveData(); // Get data in form and save.
  }
}