Hi,

Unchecking the RadioButtonTool in the click event should work. I tried it using the following code:

XAML:

                    <ig:XamRibbonGroup Caption="Group1">
                        <ig:RadioButtonTool Caption="Radio Button 1"
                                            Click="RadioButtonTool_Click"
                                            GroupName="rbgroup"/>
                        <ig:RadioButtonTool Caption="Radio Button 2"
                                            Click="RadioButtonTool_Click"
                                            GroupName="rbgroup" />
                        <ig:RadioButtonTool Caption="Radio Button 3"
                                            Click="RadioButtonTool_Click"
                                            GroupName="rbgroup" />
                    </ig:XamRibbonGroup> 

C#:

        private void RadioButtonTool_Click(object sender, RibbonToolEventArgs e)
        {
            RadioButtonTool rb = (RadioButtonTool)e.Tool;
            if (rb.IsChecked)
            {
                this.Dispatcher.BeginInvoke(() =>
                {
                    rb.IsChecked = false;
                });
            }
        }

Hope this helps,

Further clarification:

The RadioButtonTools within the group are initially set to all unchecked when the XamRibbonApplicationMenu2010 is first loaded

I would like to programmatically put these buttons back to their initial state

Thank you!