Sub CombDiffWorkbook()
pnos = ThisWorkbook.Sheets.Count
FileNames = Application.GetOpenFilename(Filefilter:="Excel File (*.xlsx), *.xlsx", MultiSelect:=True)
For Each file In FileNames
Workbooks.Open file
Set ACWB = ActiveWorkbook
ActiveWorkbook.Sheets.Copy after:=ThisWorkbook.Sheets(ThisWorkbook.Sheets.Count)
ACWB.Close False
Next file
For i = 1 To Sheets(pnos).Index
Sheets(i).Select False
Next i
Application.DisplayAlerts = False
ActiveWindow.SelectedSheets.Delete
Sheets(1).Select
MsgBox "Combining different workbooks in a single workbook Completed"
End Sub