Sorry, but saying you can't watch them tells us nothing and no one can help you without more information. Are you not able to watch programs because: 1 - You get a message saying that HBO is not part of your subscription; 2 - You get some error code like 900, 4001, 4007, 4107, 36895 etc; 3 - You see an introductory commercial and then get a message "Your video will resume shortly" and it never does; or 4 - Some other problem than one of those.
Please provide details including what operating system you're using, what web browsers you've tried and what version of Flash you're using.
- Norm