How to open up a form from another form in VB.NET?

You can also use showdialog

Private Sub Button3_Click(sender As System.Object, e As System.EventArgs) _
                      Handles Button3.Click

     dim mydialogbox as new aboutbox1
     aboutbox1.showdialog()

End Sub

Private Sub Button3_Click(sender As System.Object, e As System.EventArgs) _
                          Handles Button3.Click

    Dim box = New AboutBox1()
    box.Show()

End Sub

You could use:

Dim MyForm As New Form1
MyForm.Show()

or rather:

MyForm.ShowDialog()

to open the form as a dialog box to ensure that user interacts with the new form or closes it.