Sub test()
Dim a, x, h
Dim i&, n&, c&
Dim Myfile As Variant
Dim p, nm As String
Myfile = Application.GetOpenFilename()
If Myfile = False Then Exit Sub
Workbooks.Open Myfile
p = ActiveWorkbook.path
nm = Split(ActiveWorkbook.Name, ".")(0)
a = Sheets("sheet1").Cells(1, 1).CurrentRegion
h = Sheets("sheet1").Cells(1, 1).CurrentRegion.Resize(1)
n = InputBox("HOW MANY WORKBOOKS?")
x = Application.RoundUp((UBound(a) / n), 0)
c = 1
Application.ScreenUpdating = False
For i = 1 To n
Workbooks.Add
With ActiveSheet
.Cells(1, 1).Resize(, 2) = h
.Cells(2, 1).Resize(x, UBound(a, 2)) = Application.IfError(Application.Transpose( _
Application.Index(a, Application.Transpose(Evaluate("row(" _
& c + 1 & ":" & c + x & ")")), Evaluate("row(1:" & UBound(a, 2) & ")"))), "")
c = c + x
ActiveWorkbook.SaveAs fileName:=p & "\" & nm & i & ".xlsx"
ActiveWorkbook.Close SaveChanges:=True
End With
Next
ActiveWorkbook.Close SaveChanges:=False
Application.ScreenUpdating = True
End Sub