Newer PCs and laptops shipping with Windows 7, Windows 8, and Windows 10 no longer come with a Certificate of Authenticity attached to the back or bottom of the PC. Instead, PC manufacturers have worked with Microsoft to embed the product key directly into the BIOS or EFI.
If you need to retrieve the OEM-embedded product key from your PC, you can use the NeoSmart OEM product key utility to extract and show the product key progammed into your PC. Absolutely no user interaction is required, you just run the download and it immediately displays the detected product key. This product key can be used to reinstall Windows 10 and Windows 8 with a clean Windows setup CD to remove cruft and bloatware installed by the manufacturer, or to reinstall Windows after a crash or system failure.
Read more about the product key tool here.