How to Check My Windows Certificate of Authenticity

by Adam Parker

According to the Windows Genuine Advantage program, more than 60 million computers are running a pirated copy of Windows. That translates to one in every five computers running a counterfeit copy of Windows. It is possible to verify a Certificate of Authenticity (COA) through Microsoft to ensure that your operating system is genuine.


Review Microsoft’s guidelines to identity a genuine Certificate of Authenticity. Under optimal circumstances, do this before purchasing a new copy of Windows.


Use the Genuine Microsoft Software tool to validate the Windows product key from the Certificate of Authenticity.


Report a suspicious Certificate of Authenticity or product key to Microsoft through the How to Tell web page (see Resources).


  • check Always purchase Windows software from reputable sources.
  • check Ensure that the purchased software license matches the intended use. For example, only specific individuals and organizations can use academic licenses.


  • close Professionally counterfeited copies of Windows can look extremely realistic. Microsoft maintains a gallery of counterfeits for reference on its How to Tell web page (see Resources).

About the Author

Adam Parker has been writing professionally since 1996 and is an expert in the areas of international business development and technology. He has 15 years of global experience in 20 countries consulting businesses and governments on these topics. His writing has appeared in industry papers and journals for Citibank, Nestle and Bechtel. Adam holds a Bachelor of Science in information systems.