Condensation on the Outside of Our uPVC Double Glazed Windows
This is entirely normal for these windows and does not indicate a fault. In fact it is a sign that your new double glazing is doing what it should be doing, by not allowing any heat to pass from the inside of your house to the outside. Standard double glazed windows without energy ratings do allow heat to pass through the panes and it is this lost heat that evaporates the condensation off the outside pane of glass.
So there is nothing to worry about except realize that your boiler is no longer in overdrive and you are saving money!