Just noticed on my Devices menu a pop-up stating that from 3 November you must install the Now TV Player executable to be able to continue watching Now TV on a Windows 8 or 10 PC.
What this suggests strongly to me is that the Now TV Windows App that has been available from the Windows Store is about to be blocked. This app hasn't been updated for years but was a handy big screen interface with single sign-on that was remembered.
From now on you can only access your content from this website which has to be logged into each time.
I am guessing that with its age the Windows app was a security risk and support has now been concentrated on the Windows Player application.
However be warned - swapping from the old Windows store app to the Player application will count as one of your monthly device swaps.