My Microsoft product came with a Certificate of Authenticity. Is that my End-User License Agreement (EULA)?

From Microsoft Outlook 2002 Help
No. The Certificate of Authenticity is a security device that accompanies all Microsoft products distributed with a computer by an OEM (original equipment manufacturer).

The Certificate of Authenticity is used to assure the end user that the software program(s) accompanying the computer system is legally licensed Microsoft software. For instance, if you purchased a computer system from a computer store and it came with Microsoft MS-DOS and Microsoft Windows operating system software preinstalled on the hard disk, two separate Certificates of Authenticity should also be included inside the computer box. The Certificate of Authenticity contains anti-counterfeiting devices, such as the thermochromic heat-sensitive ink that lightens when warmed, to prevent the production of counterfeit Microsoft products. If you suspect you might have pirated software, or you have concerns about the legal ramifications of using such software, see the questions in this Help document concerning software piracy.