When you activate Microsoft Office, you must enter a product key. If for any reason you need to change the product key in Office 2010, you have two options. You can change it from within any Office 2010 application, or you can change the product key from the Windows Control Panel. Select the option that seems easiest to you.
Change the Product Key from Backstage View
The first location where you can change the Office 2010 product key is in “Backstage View” of any Microsoft Office 2010 program, such as Word, Excel or Publisher. You have probably noticed that the Office Button from Office 2007 is gone and has been replaced by the File tab. When you click this tab, you are taken to what is called “Backstage View.” You can learn more about Backstage View in Bright Hub articles such as Migrating from Microsoft Access 2007 to Access 2010: What’s New in Access 2010?, Ribbon Customization Options in Office 2010 and Office 2010 PDF Features.
In Office 2010, change product key in Backstage View by going to the File tab and clicking the Help tab in the left pane of the window.
Click the Change Product Key link in the About section of the window. The Product Activation window will open. Type your new product key into the box and then wait while your key is validated. Once it has been validated, click the Continue button. Click the Install Now button and wait while Office 2010 is configured with the new product key.
Change the Product Key from the Control Panel
The second option you have is to change the product key via the Control Panel. Click the Start button and select Control Panel from the right pane of the Start Menu. Select Add or Remove Programs if you are using Windows XP or Programs and Features if you are using Windows Vista or Windows 7. If you do not see Programs and Features, click on Programs first and then select Programs and Features.
Find Microsoft Office 2010 in the list of currently installed programs. Click to select it and then click Change.
On the Change Your Installation of Microsoft Office window that will appear, click Enter a Product Key and click the Continue button. Enter your product key in the field provided and click the Continue button. Click the Install Now button and wait while Office 2010 is configured with the new product key.
Restart a Microsoft Office application. You may need to wait while it is configured with the changed product key. When configuration is complete, you are done.