TTax Activation is a mess. My issue was the result of using removable USB drives that made TTax think it was a different computer. Others have had issues with the local PC reach the TTax validation server during startup, making the software prompt the user for a new activation code. At this point, TTax doesn't have much credibility in this area. Call the tech support line and prepare for a long hold and a long call, but worst case is they will provide you a new code. But I'd try to posted solutions first, since it can be a loooong wait.
