Good to mention your original was 4:3. Also if this works can I ask that you go back to the other forums where you asked because otherwise folk may be working away on it whan you already have an answer.

Sub splitFiles()
    Dim tempR As Presentation
    Dim opres As Presentation
    Dim L As Long
    Dim oFolder As String
    'requires v. 2010 or later
    On Error Resume Next
    Set opres = ActivePresentation
    Set tempR = Presentations.Add
    tempR.PageSetup.SlideSize = opres.PageSetup.SlideSize
    oFolder = Environ("USERPROFILE") & "\Desktop\Files\"
    MkDir oFolder
    For L = 1 To opres.Slides.Count
        opres.Slides(L).Copy
        tempR.Windows(1).Panes(1).Activate
        Call CommandBars.ExecuteMso("PasteSourceFormatting")
        Call tempR.SaveCopyAs(oFolder & "Slide" & CStr(L) & ".pptx", ppSaveAsOpenXMLPresentation)
        tempR.Slides(1).Delete
    Next L
    tempR.Saved = True
    tempR.Close
End Sub