Office 2008: How to change the CD key

Administrators, you already know the reasons you might need to change the product key on an Office installation, so I won’t need to explain or justify them here. Unfortunately, questions about this procedure are met with a terse response from Microsoft, blog posts about the procedure are way out of date, and the responses you’ll find in forum threads manage to be unhelpful, despite their unspoken self-righteous condemnation of your presumed piracy.

Making matters worse, the procedure offered by Microsoft is a pack of lies that will guide you to total removal of Office on your system; at least, Microsoft removed in 2008 the function they describe for Office 2004. And on top of that, reinstalling Office after following this or any other procedure still won’t clear the registration information.

To change the serial number, product key, CD key, license key, or whatever you want to call the string of characters required to activate a Microsoft product on an existing installation of Office 2008 for Mac, follow these simple steps:

  1. Quit all open Office applications to prevent them from clobbering your work
  2. Delete the file /Applications/Microsoft Office 2008/Office/OfficePID.plist
  3. Delete the file ~/Library/Preferences/Microsoft/Office 2008/Microsoft Office 2008 Settings.plist
  4. Launch one of the Office applications to go through the Setup Assistant and enter the new license key


  • Removal of both these files is important, as they appear to back each other up and will “repair” each other when you launch Office.
  • There’s no need to disconnect the network, as suggested in Microsoft’s note.
  • You can modify OfficePID.plist directly to change the registered name, but the serial number is not stored here, so …good idea, but no dice. Only the Setup Assistant can deal with a new license key.
  • You may want to delete the “Microsoft Office 2008 Settings.plist” file from the home directory of every user on the system, to prevent one of them logging in and repairing the OfficePID.plist file with stale information. This happened to me once, logging in with my username and then switching to another user, but I couldn’t make it happen again, so I can’t tell exactly what happened.

I’m fairly annoyed that the “Remove Office” tool described in Microsoft’s technote doesn’t behave as described. Holding down the Option key never actually reveals any “Remove License Information Only” button in the tool that comes with 2008. Another fine oversight.

Hopefully this will be the worst snag in your deployment of Office 2008. Unfortunately, however, I have a feeling I have a few more things along these lines yet to post. Good luck.

9 Responses to “Office 2008: How to change the CD key”

  1. Meff Says:

    Do you have to force quit Microsoft Daemon before making any of these changes?

  2. John Says:

    Apparently not. Launching and quitting the daemon doesn’t seem to examine or modify these files.

  3. Andrew McNaughton Says:

    Sorry, somebody has to say it… you just slated Microsoft for its oversight in your opinion. Clearly you have no sight whatsoever. The article that you referred to is very clearly, specifically for Office 2004. I’m so embarrassed for you. It works brilliantly with Office 2004. The feature was simply removed from Office 2008. Microsoft is always very clear in their knowledge base articles about which products they refer to. There was no doubt on that page that it did NOT refer to Office 2008.

  4. Sam Says:

    Thanks to author, i appreciate it.

    Sorry, somebody has to say it…. Andrew McNaughton you are an IDIOT.

  5. john Says:

    Andrew McNaughton, you have a point my friend. Although I haven’t checked, you may be right. However, Microsoft is not your best company for ass kissing. Neither is Apple or any other stupid developer who implements such drastic measures and keeps on spying on you. As for your personal insults addressed to the author, completely uncalled for. Just because you noticed the small difference in one number (4 instead of 8) it doesn’t mean people who haven’t noticed are blind and utterly embarrassing themselves.

    Yes, I have a problem with kiss ass people. Especially when they kiss Microsoft’s ass, or Apple’s ass or any other company’s ass. Come on dude, you just PAID for the product they offer, you don’t need to KISS their ass. They should kiss your hand for deciding to invest that huge amount on some basic office tools which should be part of the operating system itself. But until the world becomes “normal”, we have to buy crap from businesses that have one goal: make money. Still want to kiss their ass?

  6. john Says:

    for the record, I’m a different john.

  7. Chris Says:

    Thanks for the post…this worked like a charm for Office 2008. Deleted the two files, ran the setup assistant and put in the correct product key. Everything is working fine and it took no time at all.

  8. Brendan Says:

    Thanks very much for this. M$’s own website failed to mention the two files and as you’ve stated, getting rid of only one just restores the other. Cheers.

  9. Matthew Young Says:

    Thanks. Nothing more obnoxious then dealing with people who are positive that you’ve pirated something because of problems like this. People need to get it through their heads that software pirates don’t HAVE these types of problems. They come up with cracks to deal with it and laugh at sad attempts to create copy protection. Meanwhile, people like me; who paid full price for the product, installed it using the first serial number on the sticker, and then had a co-worker use the same serial number because she didn’t realize it had been used, end up getting screwed and having to jump through all these hoops just to use a product that I paid a hefty fee for. I HAD 3 legit keys, all I wanted was a way to input my second key on one of the systems. God it’s frustrating!

    Anyway, your solution did the trick. Thanks a mil!