Private Declare Function GetSystemMetrics Lib "user32.dll" ( _
  ByVal nIndex As Long) As Long 
 
' 2 der GetSystemMetrics Konstanten
Private Const SM_CXSCREEN = 0
Private Const SM_CYSCREEN = 1
Private Sub Command1_Click () 
  Dim ScreenX As Long
  Dim ScreenY As Long 
 
  ScreenX = GetSystemMetrics(SM_CXSCREEN) 
  ScreenY = GetSystemMetrics(SM_CYSCREEN) 
 
  MsgBox "Die Bildschirmauflösung ist " & ScreenX & "x" & ScreenY
End Sub

An sich gibt es nie Probleme, nur einen Weg, um sie zu l?sen.