Over a year ago we published a tip detailing how to change the serial number on an installed copy of Microsoft Office X or Microsoft Office 2004. That tip described a technique for digging around in library preferences, and hunting down an invisible OfficePID file.

It turns out there is a much, much, easier method!

The Remove Office tool that comes with Microsoft Office 2004 has a hidden feature that removes the serial number on installed copies of Microsoft Office (both version X and 2004).

Tip: You can find the Remove Office app in the Microsoft Office 2004 application folder inside the Additional Tools folder.

When you see the the initial “Welcome to Remove Office” splash screen, hold down the Option key. The Continue button will change to read “Remove Licensing Information Only.”

When you click the button, a second screen appears warning you that “files you no longer need must be removed from your computer.” These files include that difficult OfficePID file. Make sure all your Microsoft Office applications are not running, and click “Remove.”

The Remove Office tool will process for a bit. When it is done you can quit (ignore the warning that nothing was removed). When you launch Word, Excel, PowerPoint or Entourage the next time, you’ll be presented with the opportunity to enter a new serial number.

Now, that’s much easier! No hidden OfficePID file, no preferences.

Tip: What if you need to change the serial number for Microsoft Office X, and don’t have access to 2004’s Remove Office tool? Here’s a trick: Download the free Office 2004 Test Drive which includes the needed Remove Office tool!

Source: The difficult version of this tip (Tip #43 Change Microsoft Office’s serial number) was published on May 30, 2005. Since then about 50 people a day have visited that tip through various Google searches. We were delighted to discover this easier technique on the great Mac OS X hints website.