Yeah, boards been timing out and wanting me to keep logging back in every minute so not sure what the issue maybe. I'll give it a go again. Least I could do for your help. 
Sub processCells(ByVal Target As Range)

    For Each cell In Target.Cells
        With Range("B" & Target.Row).Select
            With Selection.Validation
                .Delete
                .Add Type:=xlValidateList, AlertStyle:=xlValidAlertStop, Operator:= _
                xlBetween, Formula1:="=Sheet2!$A$1"
                .IgnoreBlank = True
                .InCellDropdown = True
                .InputTitle = ""
                .ErrorTitle = ""
                .InputMessage = ""
                .ErrorMessage = ""
                .ShowInput = True
                .ShowError = True
            End With
            MsgBox "New employee is probationary."
        End With
    Next cell
End Sub