Authored by Martin Borve [MSFT] In 2009 we posted a detailed description of how Windows 7 enumerates a USB device . In Windows 8, we’ve made modifications in the USB driver stack on how the stack enumerates USB 2.1, 2.0, and 1.1 devices. Those modifications support new USB features and improve...

Authored by Andrea Keating [MSFT] If you have upgraded a system with USB 3.0 controllers from Windows 7 to Windows 8 and notice that the connected USB 3.0 devices are not operating at SuperSpeed (see How to determine if a USB device is operating at SuperSpeed ) then this article will help you troubleshoot...

Authored by Vivek Gupta [MSFT] Windows 8 supports a new device power state called the D3cold state . Adopting D3cold for USB presents some unique challenges for USB devices and drivers. In this blog post, I will talk about those challenges and certain restrictions. This post assumes that you are familiar...

The Microsoft USB Test Tool (MUTT) software package contains test tools for hardware test engineers to test interoperability of their USB controller or hub with the Microsoft USB driver stack . The package contains two downloads: the tools package and a readme document. The tools package contains...

Authored by Philip Ries [MSFT] Windows 8 provides a USB driver stack to support USB 3.0 devices. The Microsoft-provided USB 3.0 driver stack consists of three drivers: Usbxhci.sys, Ucx01000.sys, and Usbhub3.sys. All three drivers work together to add native support to Windows for most USB 3.0 host...