Seems you're looking for:
Popup window in winform c# - Stack Overflow[
^]. Take a deep look at solution provided by Philip Stuyck, but seems you can achieve that much, much easier. You can add another form (let say:
MyPopupForm
) and show it in non-modal mode:
Dim myPopup As MyPopupForm = New MyPopupForm()
myPopup.Show(Me)