Adobe 8 Pro files missing

To remove it from the list you can do the following:
Open the Microsoft Office program.
Go to Help > About [program name].
Click Disabled Items.
Select Adobe PDF from the list and click Enable.
Quit the Microsoft Office program and then restart it. 

(this from Adobe themselves:

http://kb.adobe.com/selfservice/viewContent.do?externalId=330984&sliceId=1

Regards

Cormac O'Loughlin

Foundry Information Technology Ltd. Highrath, Maddoxtown, Co.Kilkenny. www.foundryit.ie Tel. 00353879333050