I have 2 checkboxes one to select "YES" and another to select "NO", I have validated some controls like textbox or combobox with the ErrorProvider control, I wonder if that validation can be done with a checkbox so that the symbol of error next to the control, what I want is to avoid the MessageBox to make it more user friendly.
Of course you can, but for the case you raise, you should use a RadioButton control if you only have two options and only one is required at the same time.
But here is an example of validation with CheckBox :
if (checkBox1.Checked == false)
errorProvider1.SetError(checkBox1, "Requiere Selección.");
else
errorProvider1.Clear();