I have downloaded the TV anywhere program from the Virgin media web site and registered my lap top (the only) device. I go to watch now and it is asking me to register my device which I have and is acknowledged.....
I am sorry to hear that the laptop you registered is asking for it to be registered again when using TV Anywhere.
When you sign into your account, under My Profile, click on Device Settings. I can see from my side that there are 2 devices registered for TV Anywhere. Is the laptop one of the two that is registered? If so make sure that you are using Internet Explorer or Firefox to use TV Anywhere. Also make sure that Adobe Flash Player is up to date.
If you have tried this and it still gives the same message, remove the laptop from the registerations, then go back into stream a channel through TV Anywhere then hopefully it will prompt for registration again. This should then work for you.