To help you verify that you are using genuine Office or Windows software, 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 to activate a counterfeit or non-genuine copy of Office. Click here to validate your software now.

You can also use the Office Comparison Guide and Windows Comparison Guide to compare the special piracy prevention features of your installation discs and Certificate of Authority (COA) with those included with genuine Microsoft software. Plus, our Counterfeit Gallery shows real-world examples of confiscated counterfeit software. The more you know about counterfeit software, the easier it will be for you to ensure you always purchase genuine Microsoft software.