Hi Jake

If you set a reference to the Microsoft Powerpoint Object Library then
you could try it like this:

Private Sub Workbook_SheetChange(ByVal Sh As Object, _
ByVal Target As Excel.Range)

If Range("A1").Value 10 Then

Dim ppApp As PowerPoint.Presentation

Set ppApp = GetObject("C:\temp\pptShow.pps")
ppApp.SlideShowSettings.Run

End If
End Sub

Hope this helps
Rowan

JakeyC wrote:
Yes, I'd like it to start the show. I realise my '.ppt' extension was
misleading - the one I used in the end was '.pps', however both seem to
launch an empty powerpoint.