Windows: Driver Kit 8.1 'link'

But for the thousands of legacy PCIe cards, proprietary USB devices, and industrial control systems running Windows 7 Embedded?

As of 2023, you cannot sign a driver built with WDK 8.1 for the latest versions of Windows 10/11 without jumping through hoops.

WDK, Windows Driver Kit, KMDF, Windows 8.1, Legacy Drivers, Visual Studio 2013 windows driver kit 8.1

Microsoft requires and EV Certificates with cross-signing. While WDK 8.1 supports SHA-2 (via updates), it does not support the modern attestation signing process required for Windows 10 1809+.

WDK 8.1 supports two primary driver models: But for the thousands of legacy PCIe cards,

Microsoft has moved most old WDKs to the "Archived" section of the Windows SDK archive.

While it wasn't a revolutionary leap like WDK 8, version 8.1 polished the edges: While WDK 8

You cannot easily use it with VS 2022. If you try to install the WDK 8.1 .iso today, it will complain about missing VS 2013 dependencies. For modern developers spinning up a legacy VM, this means you are committing to running Windows 8.1 or Windows 10 (1607-ish) with VS 2013 installed.

The single biggest reason to still have WDK 8.1 installed on a build machine is .

Compile Kernel-Mode Driver Framework (KMDF) and User-Mode Driver Framework (UMDF) projects.