How can I prevent a RadioButton from being checked when the Form loads?

Question

I can't seem to prevent my form from checking one of the Radio Buttons in my Group Box:

As shown in the designer, no Radio Buttons are checked there.

Below is just about all of the code for this simple form. Nothing calls for a Radio Buttons to be checked here or in the form's designer.

Q: Is there a way to prevent any Radio Button from being checked when the form loads?

public ValueTypeSelector() {   InitializeComponent();   radioButton1.Checked = false;   radioButton2.Checked = false;   radioButton3.Checked = false;   radioButton4.Checked = false;   radioButton5.Checked = false;   radioButton6.Checked = false;   button1.Enabled = false;   button1.Click += clickEvent;   button2.Click += clickEvent;   radioButton1.Click += clickEvent;   radioButton2.Click += clickEvent;   radioButton3.Click += clickEvent;   radioButton4.Click += clickEvent;   radioButton5.Click += clickEvent;   radioButton6.Click += clickEvent; }  void OnShow(object sender, EventArgs e) {   foreach (RadioButton rad in Controls) {     if (rad.Checked) {       Console.WriteLine("WTF?");     }   } }  void clickEvent(object sender, EventArgs e) {   RadioButton rad = sender as RadioButton;   if (rad != null) {     if (rad.Checked) {       if (rad == radioButton1) {         DataType = TableDataType.Boolean; // <= HERE IS THE PROBLEM! FIRES ON FORM LOAD       } else if (rad == radioButton2) {         DataType = TableDataType.Character;       } else if (rad == radioButton3) {         DataType = TableDataType.DateTime;       } else if (rad == radioButton4) {         DataType = TableDataType.Decimal;       } else if (rad == radioButton5) {         DataType = TableDataType.Integer;       } else if (rad == radioButton6) {         DataType = TableDataType.String;       } else {         return;       }       button1.Enabled = true;     }   } else if (sender == button1) {     DialogResult = DialogResult.OK;     Close();   } else if (sender == button2) {     DialogResult = DialogResult.Cancel;     Close();   } } 

UPDATE: The problem is that radioButton1 gets checked when the form is shown:

      if (rad == radioButton1) {         DataType = TableDataType.Boolean; // <= HERE IS THE PROBLEM! FIRES ON FORM LOAD       } else if (rad == radioButton2) { 

Answer 1

Make sure your radiobuttons are NOT the first tabindex = 0 controls. Make the OK button tabindex=0, followed by the radiobuttons.