Microsoft made Windows 10 available today, free upgrade for v7 and v8 users. The spec says:
“Secure boot requires firmware that supports UEFI v2.3.1 Errata B and has the Microsoft Windows Certification Authority in the UEFI signature database.”
For more information on Window 10’s firmware/hardware security requirements, look at Microsoft’s talk from the last UEFI Forum plugfest, from May: “Overview of Windows 10 Requirements for TPM, HVCI and SecureBoot“, by Gabe Stocco, Scott Anderson and Suhas Manangi (Microsoft):
More Information:
http://www.microsoft.com/en-us/windows/windows-10-specifications
Firmware Security 