Are you using valid product id. please check the system date and time before using license.
In your Windows Start menu there is a separate program icon for "Manage Tableau Licenses" under the Tableau Server. You should start there (assuming the host has full Internet connectivity.)
If you are unable to assign and Activate your license key there, then that is likely your problem.
At that point you probably should call the phone number given.
This may explain it...
This is Mac but the error looks like yours...
This maybe useful (if internet access is a problem)
Hope that solves it, otherwise as Ken mentioned, contact the telephone number given in the error message