It's still possible to cast NOW TV with a Windows PC, despite the fact you can no longer cast from Chrome.
I installed Bluestacks to my Windows 7 PC, added my Google sign in details and was able to add Android apps, including the Now TV app, which I was able to cast to my Chromecast. You get 20GB of storage, so if you want to free up space on your phone/tablet, install all the apps you use on Chromecast, such as Netflix, All4 and BBC iPlayer on Bluestacks instead.
As you can see below, I was able to cast Only Fools and Horses, using my PC.
