Como saber si la versión de Office 2003 es Beta o Final

El proceso vendría descrito en este articulo de la KB

Numbering scheme for product code GUIDs in Office 2003

En resumen, el proceso consisitiria en buscar desde regedit esta clave.

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Uninstall

Encontrarás una clave parecida a esta.
{WXYYZZZZ-6000-11D3-8CFE-0150048383C9}

W es el tipo de version y equivale a esto.

0       Any release before Beta 1
1       Beta 1
2       Beta 2
3       Release Candidate 0 (RC0)
4       Release Candidate 1 (RC1)/OEM Preview Release
5-8     Reserved values
9       Release to manufacturing. This is the first shipped version (initial
release).
A       Service Pack 1 (SP1) (Unused if the product code is not changed after
release to manufacturing)
B       Service Pack 2 (SP2) (Unused if the product code is not changed after
release to manufacturing)
C       Service Pack 3 (SP3) (Unused if the product code is not changed after
release to manufacturing)
D-F     Reserved values