Assuming that the first form creates and shows the second form, a couple
ways come to mind. You could create a property on the second form that holds
the boolean and then push the boolean into that property before showing the
new form...
Form2 f = new Form2();
f.BoolProp = true;
f.Show();
Or you can create a constructor overload on the second form that accepts a
boolean...
Form2 f = new Form2(true);
f.Show();