Microsoft KB Archive/817813

= Add/Remove Hardware Wizard Appears When You Attach a USB 2.0 Hub =

Article ID: 817813

Article Last Modified on 2/21/2007

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APPLIES TO


 * Microsoft Windows 2000 Advanced Server
 * Microsoft Windows 2000 Server
 * Microsoft Windows 2000 Professional Edition

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SYMPTOMS
After you install a hotfix that updates the Usbhub20.sys file and then you attach an external Universal Serial Bus (USB) 2.0 hub to a USB 2.0-enabled port, the Add/Remove Hardware Wizard may prompt you to install the driver for the USB 2.0 hub.



CAUSE
When you attach a new USB 2.0 hub to a computer, Windows detects the hub as a new device and starts the Add/Remove Hardware Wizard.



WORKAROUND
To work around this issue, follow the instructions in the Add/Remove Hardware Wizard to install the driver for the USB 2.0 hub.



STATUS
This behavior is by design.



MORE INFORMATION
This behavior does not occur on a Microsoft Windows XP-based computer (after you install a Windows XP hotfix that updates Usbhub.sys) because the architecture of the USB 2.0 driver stack in Windows XP is different from the one in Windows 2000. The Windows XP USB driver stack supports both USB 1.1 and USB 2.0 specifications. The Windows 2000 USB driver stack was designed to support only USB 1.1, with USB 2.0 support added later.

After the first release of Windows 2000, Microsoft added USB 2.0 support through additional drivers. For example, in Windows XP, Usbhub.sys supports both USB 1.1 and USB 2.0 hubs. In Windows 2000, Usbhub.sys supports USB 1.1 hubs, and Usbhub20.sys supports USB 2.0 hubs.

This behavior also occurs with other device drivers that are associated with a Functional device instead of a Physical device. Examples of such drivers include the following:
 * Mf.sys (Multifunction Enumerator)
 * Sbp2port.sys (SBP-2 Protocol Driver)

