Sub CreateSlides()

Dim OWB As New Excel.Workbook
Set OWB = Excel.Application.Workbooks.Open("C:data.xlsx")
Dim WS As Excel.Worksheet
Set WS = OWB.Worksheets(1)

For i = 1 To WS.Range("A1000").End(xlUp).Row

    ActivePresentation.Slides(1).Copy
    ActivePresentation.Slides.Paste (ActivePresentation.Slides.Count + 1)

       ActivePresentation.Slides(ActivePresentation.Slides.Count).Shapes(1).TextFrame.TextRange.Text = WS.Cells(i, 1).Value
Next
End Sub