Step1: Click on the button to open the Start Menu. Now, click on the Control Panel and then click on Programs (Uninstall a program), and finally click on Program and Features.
(Windows XP users: Start > Control Panel > Add or Remove Programs.)
Step2: From the list of installed programs, find Microsoft Office Professional Plus 2010 (or your installed version of Office 2010 or Office 2013) or Microsoft Office Visio Professional 2010 (or your installed version of Visio 2010), which ever’s key you want to change, select it and then click on Change.
change product key office 2010
Step3: From the newly opened dialog box, select the Enter a Product Key option, and then click Continue.
Step4: Type your new product key and check the option that says Attempt to automatically activate my product online to automatically activate your Office 2013 or Office 2010 suite. Now click on Continue and then on Install Now.
If your office key is not valid, you need buy a new office key. I recommend you to visit go2keys.com. yesterday was my 5th purchase from their site.
Everytime I am amazed at the prices and customer service.
I have recommended this site to many friends. the fact will prove my words.
Note: Your computer must be connected to the Internet if you want to reactivate Office 2013 or Office 2010 online.You can also activate Office 2013 or Office 2010 later by running any Office 2010 app, and then clicking on the File tab > Help.