After installing an update and launching the program says you are not registered, but you are. This screen comes up for all users but is intended for new users only.
Occurance
After installing an upgrade, for example, from Xpress Pro 5.x to another 5.x version, or Xpress Pro 4.x to 4.x.
When you launch the software it may say you are not registered and ask you to register, if you are already registered you do not need to register again.
This screen comes up for all users, but it is intended for the brand new user who just puchased the software for the first time.
Solution:
If you are an upgrade user and have allready registered, the following will walk you through the procedure to prevent that message from comming up again.
When launching Xpress Pro, the Splash Screen will appear.

After an upgrade, or a new install a Licence Agreement window will come up.

When you are finished reading the License Agreement, Choose Yes .
Another Dialogue Box will come up and prompt you to register your copy of Avid Xpress Pro.

If you have not registered your copy of Avid on our website, and your computer is connected to the internet, clicking the button "Register on the Web" will take you to the Avid Xpress Product Registration page. Otherwise you may register by clicking on the following link: http://www.avid.com/register/
If you have allready registered, Click "Don't Register Now ". You will then be taken to the Project Select window.
Within the next few launches of the Avid Xpress Software, the License Agreement Window will have a new Button that says "Yes, and Don't Show Again ."

Click that button.
A New Dialogue Box pops up and prompts you to enter the Licencee or the organization that owns the software.

Type the name of the Company or Person(s) that own the software and click OK .
The Product Registration Dialogue box comes up again.

Click "Don't Register Now ."
The next time you launch your Avid Editing application, you will see the name of the Licencee in the Splash Screen with the date you entered the name into the Orginization Name Dialogue box. This date is not representative of the actual date the user registered the software on the Avid.com website.

You May need to enter this information after an uninstall/reinstall of Avid software, since some installer applications do not preserve this file. You may make a backup copy of this file if you wish.
the default file location is C:\Program Files\Avid\Avid Xpress Pro HD\Settings\Avid License Data

For More information on backing up files, See Chapter 1 of the User Manual, Working With the Desktop.
Note: Not all Avid Edting applications have the same splash screen or file location path. the example above used Avid Xpress Pro HD.