I just received a CD with Office2003 & appology letter from microsoft for the problem with VSTO & moving from Office 2003 Evaluation to Office 2003.
From the letter:
"...We recently discovered two issues that can prevent installation of VSTO [Visual Studio Tools for Microsoft Office System]. First, VSTO is not compatibel with Microsoft Office System Evaluation 2003 ('Office Trial'). Second, users that upgrade from Office Trial to a full version of Offcie 2003 can still have problems if they don't follow the correct upgrade procedures.
In the first case, Microsoft distributed copies of VSTO with Office Trial, implying that the two should work together. This is not the case. Customers who received this combination can still use Office Trial to evaluate Office 2003. When a user tries to install VSTO on Office Trial, installation will fail with an error message indicating that an office pre-requisite is not present on the PC. To help with this issue, we have included a complimentary copy of Office 2003 that will work with VSTO.
In the second case, in order for VSTO to correctly recognize the full version of Office 2003, the user must first completely uninstall Office Trial by going to the Windows Control Panel and choosing Add or Remove Programs. After completing this, and then installing the full version of Office 2003, VSTO should install as expected.
We sincerely apologize...."
http://support.microsoft.com/default.aspx?scid=kb;en-us;828087