Office 2008 SP1 Released with Infinite Looping Setup Assistant
Service Pack 1 for Office 2008 was just released recently. However, many people (including me) have experienced the infinite looping setup assistant problem. Basically, you can’t get any of the Office Apps working. If you try launching any of the Office apps, it would bug you with the Setup Assistant over and over again.
So here’s how to fix it:
Make sure you have your CD Key ready.
Navigate to ~/Library/Preferences/Microsoft/Office 2008 (you can use the Finder’s Go => Go To Folder… feature, just cut and paste this into the box)
Delete Microsoft Office 2008 Settings.plist
then Navigate to /Applications/Microsoft Office 2008/Office/
delete OfficePID.plist
You will be asked for the CD Key the next time you launch any of the Office apps. But that’s about it, it should fix the “Setup assistant loop” problem. ;)

Hi, thanks for investigating this. I tried the above, but when I put in the product ID, it won’t let me “continue.” Did you encounter this problem?
Hmm, you might have mistaken the product ID (which is produced after you set up the product) with the key. You sure you put in the key properly without typo?
yeah i had the same problem, put the product key in and nothing happens, this is so annoying. and if you put a different one in it says it is not valid
Thank you so much! talk about office being annoying…it seemed a bunch of people were/are having this issue. I’m usually hesitant about deleting .plist(s) since some programs have trouble recreating them again, but this worked great.
thanks.