Personally I don't use my laptop to watch NOW on, so apart from this troubleshooting link all I can provide you is another link for Live chat.
Live chat, just make sure to click "chat online"
Found a solution for my problem ...
I have a sound card for better quality sound than the mother board. The software to manage the sound-card must not be running when Now player is launched.
Closing the software (including in hidden icons) allows Now player to run.
I can then relaunch the sound software to manage things like head-phones vs speakers.
@teresaPhave a look at other programs running on your PC, especially things that might have changed around the time Now player stopped working. That's how I solved my issue.
OT: @gavs82008 For some reason chat online doesn't work for me (I use Firefox).