Screen Resize Issues

[Blinky Bill]

Hey Guys,
I got some code from this forum to resize the screen to a specific size that i specify. I have attached the .bas file for your perusal. My problem is that i need the code to resize the screen to 1024x768 if the current size is smaller. The program is supposed to either resize the screen or abort execution if it cannot. This is the code i use to do it

Public Sub ResizeScreenTo1024()
    Dim r As Integer
    
    'try to set the screen res here
    'get the screen resolution and color depth
    originalResolution = GetScreenResolution()
    originalDepth = GetAvailableColours()
    
    xOriginalWidth = GetCurrentXSetting
    yOriginalWidth = GetCurrentYSetting
    
    'try to change the resolution to 1024 x 768 with 32,24,16,8,4 until success
    If (xOriginalWidth < 1024) And (yOriginalWidth < 768) Then
        Call ChangeScreenSettings(1024, 768, 32)
        If changeSuccessful = False Then
            '32 failed, try 24
            Call ChangeScreenSettings(1024, 768, 24)
            If changeSuccessful = False Then
                '24 failed, try 16
                Call ChangeScreenSettings(1024, 768, 16)
                If changeSuccessful = False Then
                    '16 failed, try 8
                    Call ChangeScreenSettings(1024, 768, 8)
                    If changeSuccessful = False Then
                        '8 failed, try 4
                        Call ChangeScreenSettings(1024, 768, 4)
                        If changeSuccessful = False Then
                            r = MsgBox("Your computer cannot operate this software.", vbCritical, "VideoVision 1.0")
                        End If
                    End If
                End If
            End If
        End If
    End If
End Sub

Now what actually happens is that on some computers the screen doesn't actually change size, but the program begins execution, when it should abort. Also on some computers, the screen sometimes resizes and sometimes doesn't. Is it possible that this code is the cause of this? Or is it more likely to be an individual computer issue? If so, is there some more dynamic code to resize the screen of these computers?

Hoping someone can help,

Regards