Voici ce que j'ai trouvé sur le site d'Adode et ça l'a fonctionné pour moi!
PDFMaker is unavailable in a Microsoft Office application (Acrobat 7.0, Acrobat 3D on Windows)
Issue
The PDFMaker icon (Convert To Adobe PDF) and the Acrobat menu are missing from a Microsoft Office 2003, XP, or 2000 application (for example, Access, Excel, Word).
Solutions
Do one or more of the following solutions:
Solution 1: Remove Adobe PDF from the Disabled Items list in the Microsoft Office application.
1. Open the Microsoft Office program (Word, Excel, Publisher, or Excel).
2. Go to Help > About [program name].
3. Click Disabled Items.
4. Select Adobe PDF from the list and click Enable.
5. Quit the Microsoft Office program and then restart it.
Note:Microsoft Office Applications disable add-ins as a failsafe if the application is prematurely closed (for example, system wasn't shut off properly or the application crashed).