Genuine Microsoft Office® provides unique value, ongoing updates, and enhancements from Microsoft that counterfeit versions of Office do not. With genuine Office, you'll spend less time keeping your software current and more time generating professional-looking documents for home or school.
When you buy genuine Office, you:
Know that you are getting the most secure version of Office available.
Have the confidence that you got what you paid for.
Have access to support from Microsoft or a trusted partner.
Stay better protected with the latest enhancements.
Enjoy access to the latest offers exclusively reserved for genuine Microsoft software users
How can I tell if my copy of Office is genuine?
To help you verify that you are using genuine Office, Microsoft offers a quick and easy online process called validation.
Validation takes only a few moments, and enables Microsoft to create a match between your PC's hardware profile and your 25-character Product Key (located on the Certificate of Authenticity), which Microsoft stores and checks against future activation and validation attempts. We do this to ensure that your Product Key is not used by another person in a malicious manner, such as activating a counterfeit or non-genuine copy of Office.
You can also use the Genuine Office Comparison Guide to compare the special security features of your Office XP, Office 2003 or Office 2007 installation CD and Certificate of Authenticity (COA) with those included with genuine Microsoft software.
Will I be asked to provide personal information during validation?
Microsoft values your privacy, and we do not collect any information, such as your name or email address, that can be used to identify you or contact you.
For more detail visit Microsoft Genuine Advantage