Private fm As VB.Global
 
Private Sub Check1_Click()
If Check1.Value Then
    fm.Forms(1).Show vbModeless
Else
   Unload Form2
End If
End Sub
 
Private Sub Check2_Click()
  If Check2.Value Then
    fm.Forms(2).Show vbModeless
Else
   Unload Form3
End If
End Sub
 
Private Sub Check3_Click()
 If Check2.Value Then
    fm.Forms(3).Show vbModeless
Else
   Unload Form4
End If
End Sub
 
Private Sub Form_Load()
  Set fm = VB.Global
 
  Load Form2
  Load Form3
  Load Form4
End Sub