esta es facil!!, aki te pongo la funcion k yo utilizo siempre: comprobado k funciona:
'CAMBIO DE RESOLUCION
Private Declare Function EnumDisplaySettings Lib "user32" Alias "EnumDisplaySettingsA" (ByVal lpszDeviceName As Long, ByVal iModeNum As Long, lpDevMode As Any) As Boolean
Private Declare Function ChangeDisplaySettings Lib "user32" Alias "ChangeDisplaySettingsA" (lpDevMode As Any, ByVal dwflags As Long) As Long
Const CCDEVICENAME = 32
Const CCFORMNAME = 32
Const DM_PELSWIDTH = &H80000
Const DM_PELSHEIGHT = &H100000
Private Type DEVMODE
dmDeviceName As String * CCDEVICENAME
dmSpecVersion As Integer
dmDriverVersion As Integer
dmSize As Integer
dmDriverExtra As Integer
dmFields As Long
dmOrientation As Integer
dmPaperSize As Integer
dmPaperLength As Integer
dmPaperWidth As Integer
dmScale As Integer
dmCopies As Integer
dmDefaultSource As Integer
dmPrintQuality As Integer
dmColor As Integer
dmDuplex As Integer
dmYResolution As Integer
dmTTOption As Integer
dmCollate As Integer
dmFormName As String * CCFORMNAME '20
dmUnusedPadding As Integer
dmBitsPerPel As Integer
dmPelsWidth As Long
dmPelsHeight As Long
dmDisplayFlags As Long
dmDisplayFrequency As Long
End Type
Dim DevM As DEVMODE
Function CambiaResolucion(BitPorPixel As Integer, Ancho As Integer, Alto As Integer) As Boolean
'Parámetros :
'BitPorPixel : Nº de bits de color
' 4 - 16 colores, 8 - 256 colores
' 16 - 65.000 colores, 32 - 16 M de colores
'Ancho : Nº de pixels de ancho
'Alto : Nº de pixels de alto
Dim a&
a = EnumDisplaySettings(0&, 0&, DevM)
DevM.dmFields = DM_PELSWIDTH Or DM_PELSHEIGHT
DevM.dmBitsPerPel = BitPorPixel
DevM.dmPelsWidth = Ancho
DevM.dmPelsHeight = Alto
a = ChangeDisplaySettings(DevM, 0)
If a = 0 Then
CambiaResolucion = True
Else
CambiaResolucion = False
End If
End Function
La llamada es cantidad de facil, te la pongo
Dim a&
'Llamada a la función para cambiar la resolución
a = CambiaResolucion(16 - 65#, 800, 600)
y ya esta la resolucion cambiada
TalegoZ gente!!