If the application built as a single document interface (SDI); that is, you only ever need one instance of each of these windows, create each of the three screens as separate User Controls in Form Designer. Create one instance of each for the duration of the application, and add or remove each of these three user controls to your main form as necessary. This is a little cleaner than hiding/showing them (If they were very complex forms I might hide/show to conserve resources).
You will note that I recommend using a User Control instead of a Form. You could actually use either, but this is what user controls are meant for. There are a few reasons.
- User controls are lighter-weight.
- User controls can be added to a form in the Form Designer and you can still interact with them. Sub-forms cannot be used in the Designer.
- Forms require special preparation before being used (
Form.TopLevel = false
).