Tente algo como:
Sub Macro3()
Application.DisplayAlerts = False
ActiveWorkbook.SaveAs Filename:="C:\Users\garys\Desktop\arrr.xlsx", _
FileFormat:=xlOpenXMLWorkbook, CreateBackup:=False
ActiveWorkbook.SaveAs Filename:="C:\Users\garys\Desktop\arrr.xlsm", _
FileFormat:=xlOpenXMLWorkbookMacroEnabled, CreateBackup:=False
Application.DisplayAlerts = True
End Sub