After installing FrontPage 2003, you might
have asked yourself:
What happen to the Format->Shared
Borders menu?
The new Microsoft FrontPage 2003 is a great improvement in
many ways, adding new capabilities such as Dynamic Web Templates (DWTs),
Interactive Buttons and much more, while maintaining compatibility with
previous technologies. One of these useful technologies used in FrontLook Super
Themes are Shared Borders. The "Shared Borders..." menu in the "Format"
menu has been removed to emphasis the shift to new technologies such as
DWTs but can be easily brought back into play with a simple adjustment.
Step 1: Bring up your web in FP2003
Step 2: Bring up the "Page Options.."
Dialog from the "Tools" menu. Press the Authoring tab.

Tools->Page Options... Dialog - Authoring Panel
Step 3: Check the "Author-time Web
Components" and "Shared Border" item
Then the "Navigation" and "Shared Border" items.
Step 4: Press "OK"
You will now be able to select the "Shared Border..." menu in the
"Format" menu.
And That's It
You can still use Shared Borders in your new web by turning on the Shared
Borders menu in the Authoring panel of the Page Properties dialog.